Sure, she can call up a magelight.  Silently.  And concurrently feel sympathy-grief at the loss of such a place.  (...With a small, stifled undercurrent of frustrated rage at Eru Illuvatar's grand tragedy.)

Lindir looks.

Then he stares, intrigued, trying to unravel what's happening; whence these new tones are coming into the Song of the world.

Then, blinking, he turns his gaze to Alicia herself, looking at her.  Her body looks... well, it's been Great Years since he saw any mortal child save Aragorn, so he can't really say.  Her spirit... very well; his sight was never the best there, but he can tell apart Elves from mortals when he's looking, and she doesn't look unlike mortals?

(All this will take some time before he's satisfied, unless Alicia wants to interrupt.)

....Yeah, she'll give him a minute.

(If it takes long enough her brain starts eating away at her sanity over standing still too long, she will probably produce a (magic) notepad and start drafting some things.)

That makes him stare at the magic notepad instead for a few moments.  But then he shakes himself and remembers that mortals and children sometimes get bored, and Alicia's both of them.

<Amazing!  I doubted your story at first because it is so unprecedented, but - now I believe you.  Yet your story raises many questions.  I had thought there were no places that Eru Illuvatar had not made or caused to be made.  How do you know that Eru did not make the place you are from?  And how did you come here to Arda, and how are you still able to work 'magic' in the same ways you are at home - unlike any other person in Arda that I have heard of?

<Can you teach that art?

<And - what is in it?  We use some mathematics in our arts too, but I suspect you use other sorts?>

<In order: Many of the details that truly render me sure of that are secrets, but of the things I can tell you, I can say that the arc of my universe is not so tragic as Eru seems to prefer, for what little that means.>

<I came here because I charged a portal-frame I was working on with - raw essence of possibility, in a moment of power incontinence that, frankly, I was lucky to survive - and as to why my magics still work and whether I can teach them, I truly have not the slightest idea.  Or rather, I have some vague speculations, but nothing I would wish to put forward as truth.>

<The sort of magic that makes portal-frames is definitely heavy on the math when I do it, but that is as much a consequence of how I view the world as it is a consequence of the magic itself - magic drawing upon the cosmic principle of Order requires that you have a system of meaning, but it does not prescribe one.  There are five others, formed in equal-and-opposite pairs, as well as two 'composite' magics, formed of a combination of those primes; the basic elements of the world are also made of such stuff, though I would not say that this is likely true of Arda.  ...Osanwë is strikingly similar to spirit magic - one of those composites - which honestly surprises me, because I've never had a knack for that one, and yet here I am, having complex conversations.>

<Interesting.  Personally, I would doubt that does mean anything about Eru's preferences.  Many times in my life, I thought I could infer from the Age I was then in, to the overall arc - and each time so far I have been surprised.  Or -> He shrugs.  <Perhaps Eru could play different themes in different creations?  But you say you have other details.

<Though the fact that your familiar magics still work here makes me consider whether there might be some more fundamental harmony between the principles behind your magic and the Song behind Arda.  If Eru did in fact cause your world to be made - or conceivably if he took inspiration from the principles behind it - or if whoever else made your world took inspiration from here ->

He shrugs.  <I am speculating well in advance of information here, without even any supposition how to demonstrate any of my guesses.  Could you determine whether Arda is in fact made of these principles?  Even in concept?>

She blinks, bemused.

<...It's not made of my cosmology's primes, it's made of Song.  The Song is the fundamental building block of Arda as much as the six primes are the fundamental building blocks of my homeworld.  Whether there is some other resonance...>

<All things are within the Song, even such things as the Enemy - so it would not surprise me if there were, independently, similar leitmotifs, to use the obvious analogy?  It's hard to make worlds that don't have certain concepts, even if some of mine are more esoteric than others.>

(There are so many things she wants to answer with "I know that's not how it went because I didn't do it that way/it couldn't have happened in that order because if my personal timeline is indicative I most certainly postdate Arda", in this set of questions, but she is, thankfully, able to restrain herself.)

<That's not to say that I couldn't go look, it's just that...well, honestly, we don't have the time for it right now, unless it somehow becomes relevant to questions like 'since the world-with-Valinor-in-it is - quite probably still flat, given some of my information, and the world-without-Valinor is spherical (like planets should be, if you want to have a gravity that's not jank; the amount of things that are all but held up personally by Eru et al. instead of being an emergent consequence of simpler rules is really annoying to my sensibilities on how worlds should be built - as a writer, I hardly have practical experience -),> which is at least Kenobi-true, <what spatial geometry should I be embedding my teleportation in?'>

<...I mean, there's just no way,> she is gesturing heatedly, now, <to have a steady gravity and a finite plane without fiat, and as far as I know Valinor is hardly infinite -->

<...But that's not immediately relevant.>

He shakes his head.  <No, it is not infinite - or at least it was not before the Changing - my father went to its edge once.  But you are right; this is not relevant now.>

<You were mentioning warding...>

He looks at her appraisingly, and then glances over the various magical adornments strewn over his workbench and a set of cabinets on the wall of the room.

<Perhaps first, we can see if our arts would work on you.  Many effects that I have here would be too subtle to measure... do you have any skill at the bow?  Or at sketching?>

<Not more than a basic facility with blueprints, in the case of sketching, but it is more than I've skill in the bow, specifically - though depending on what the item that improves archery skills does, it might still improve something I am practiced in.  I - hm - well, I can definitely tell these do things...  I similarly figure that I would be able to tell if these effects do something to or for me, being as I am reasonably attuned to perceiving my own self, though I'm not as sure I'd be able to specifically tell where or how they act without more knowledge of the overall style or particular study of a given piece...>

She's going to take a closer look at what's there, modulo other instructions.

Lindir doesn't think much of humans' attunement to perceiving their selves.  Maybe Alicia's better here, but he's not going to assume.

<Hmm, perhaps if we have no other option... Singing?  Swordplay?>

Alicia can see several necklaces and bracelets, a coronet, several coat-clasps, and some less-identifiable adornments - as well as a few door-hinges and a number of nails.

Well, everybody needs hinges and nails.

<...Might be able to swing swordplay - it's more of a desperate-holdout-weapon level of training, combat magic being my particular preference - but I do know a bit about stabbing people with pointy bits of metal.>

<Ah, do you think you could strike a quoit?...>

He opens the door to one of the closed cupboards, which holds two swords wrapped in cloths.

<Most likely, yes.>

He nods, hands one sword to Alicia, picks up the other one himself, and beckons her to follow down the hall.

<The sword you have is made by the Beornings recently; it has good balance but nothing more.  The sword I have I forged several Great Years ago.  If you can strike the quoit better with mine, then I think it will be proven that our 'magic' can indeed affect you.  Which to be honest I suspect, but it is best to experiment.>

(Alicia will find the sword somewhat heavy given her age, but no more so than the swords she might've held before.  It is a good sword.)

Well, she can certainly take a stab at it, then.  (While being bemusedly amused at her own sense of humor.)

<The question is then what constitutes 'better', and how we measure that...  I could rig up a more precise hit-tracker, if that'd help, but I'm not certain...hm, but maybe I could -> measure the quality of her form, that is.  <...Wouldn't really trust that, though, I've never quite thought to do it before and I'm not certain what the right values would be, kinematically speaking....  Though things like speed and force are easy enough to measure regardless.>

Lindir nods.  <I was thinking speed and accuracy, yes... form would be helpful if you knew what form you were trying for, but I do not know what the swords would do for novices... I was never one to train children.>

Just at the end of the hallway is a door framed against an arch of branches, which Lindir opens into a grassy yard.  At the other end is the stables, with some horses' heads poking out.  Near the middle of the yard, a leather-covered ring about head-wide dangles on a long rope from an arm stretching out from a balcony overhead.

Gandalf and Halbarad are both in the yard, by the stable door, with Halbarad stroking his horse's head.  Halbarad looks up at Alicia and Lindir with surprise, raising his hand in greetings.

She waves.  <We are conducting an experiment.  ...Which, now that I think of it, is probably obviated by [CLASSIFIED INFORMATION],> she very firmly doesn't-say - to wit, the One Ring (knowing she was there and) trying to tempt her, not that that passes outside her innermost thoughts, <but we're already out here and magic swords are neat and I could probably do with the practice anyway, so we may as well see if my limited ability to sword is helped any by that one.>

"Ah!" Halbarad looks with interest when translated.  "A full-sized sword, too - and you're at the right age when my own sons started getting used to it.  I hope you were able to help the hobbit?"

<He's on the mend; I was able to find and remove what was ailing him,> she replies, once what Halbarad said is translated back.  ...She really needs to get something working for this, not everybody is Elves (or Maiar &c.,) and she can't just hope random places will have one available to play translator.

<Oh, excellent!>

Gandalf relaxes and smiles visibly.

<Yes...> Lindir adds distractedly.

"Halbarad - you are more familiar with children and mortals; can you watch Alicia's form and her hits on the quoit?"