Well poking buttons seems to be the way to go. She picks one to enact this strategy upon. Poke!

The half-tree vanishes, replaced by an indistinct cloud of smoke.

.... Okay?

Maybe it's some kind of magic touchscreen. She attempts to poke the smoke.

A little bit of the smoke moves when she drags her finger past it, coming away in a small blob.

She has no idea what's going on.

Button press? Smoke poke? What is this how does it work.

Pressing the other button brings her back to the half-a-tree. Pressing it again brings up a rather intricate-looking flower arrangement, with no smoke in sight.

She pokes the tree?

A little bit of tree comes away from the end of the branch she poked, following her finger.

Yep. No idea what's going on.

She turns it off and puts it back.

Okay. So: how does she not scream 'I have exactly zero memory of the life you think I've been living for the past fifteen years'?

Well, she has to ask herself, what would she do if she were a rich, somewhat spoiled heiress in a magic demon family. ... Save the world, clearly, but besides that.

Devour all knowledge of magic; yeah, she'll get on that, but she can't just yet because she has no idea what's going on. Get a ton of books; obviously done. She suspects the non-existent version of her has read them all, but she has no such luck. Get a good idea of the political landscape? Keep her head down until she was more experienced or was pissed off?

... She looks at the set of makeups.

And she realizes abruptly that heiress-version-of-her probably enjoyed looking pretty very much, and that she has barely any idea how to use makeup.

Welp.

Time to figure that out. Heiress-her wouldn't settle for shoddy work on her face.

Are there books on cosmetics? Yes, there is a section next to the section on influencing people. And there is a convenient mirror. This shouldn't be too hard, right...?

Right! It shouldn't be too hard. Women do this all the time, she shouldn't have any trouble.

...

Okay, eyeliner is pain incarnate and she's lucky if she can walk away from it not looking like a racoon. Mascara is annoying and she keeps missing and getting it on her eyelids. She even has trouble with the basics; how does one use foundation without looking like plastic? And blush seems to be impossible to get right without overdoing it and making her into a clown. She has actually used eyeshadow before, but pulling off anything fancy and multicolored is just not happening. The blending is wrong. And various things-that-go-on-her-lips are easy, though she has to wipe off one set and redo it in order to work better with the color of eyeshadow she picked at near-random, and how does she keep it from rubbing off everywhere and she is so screwed.

Well. She's not letting that stop her. She retrieves a beginner's book on cosmetics, finds something simple and easy and 'classic' and copies the instructions obsessively until she has something that makes her look...

She peers at herself in the mirror. She blinks. Vaguely, she recalls that the physical Augmentation she picked enhances physical beauty.

No wonder heiress-her was a bit vain.

She deems this result good enough for the short term, has a brief debate over whether she should stave off sleep some more to get started on cracking her own encryption, and decides that if she stays up much longer someone might actually hear her and wonder just why she's teaching herself things she should already long know. Beginner's books go back to their places, makeup gets wiped off, and Yvette curls up in her gloriously-big too-soft bed.

And she sleeps.

When Yvette wakes up again, a vaguely familiar-looking girl is sitting at the small table by the window. She's turned on the metal device, and is absently arranging pieces of smoke into the shape of a topiary squirrel.

Even though she's near three hundred, Yvette's new sister doesn't look very threatening - especially with the warm glow of sunrise filtering through the curtains.

...

Yvette thinks that this is not at all normal behavior, heiress-her would not tolerate it.

She stirs, and then sits up, and peers at Ishmerai. It seems more and more likely that she also got a visit from some unwanted shadows...

"Good morning," she says, a little cautiously.

"Good morning!" Ishmerai smiles, and something in her hair smiles as well, and her shadow on the floor smiles, and something in her lap smiles.

Yvette doesn't react to the multitude of unsettling smiles with anything more than a blink.

She had a creepy shadow thing on her lap for a long while last night. This is creepy, but Yvette can handle it without screeching and fleeing the room.

Ishmerai blinks, and closes her extra mouths. "Oh, um, sorry. I forgot my shadow again, didn't I? Eye?" She smiles lopsidedly, and winks from somewhere near her feet.

"So, yes. Welcome to the family. I'm sure you have a lot of questions."

"Thank you," says Yvette, blinking. "It's okay. I had a shadow thing on my lap for at least two hours, it's really hard to freak me out now. Um. How common are - we? Did we even get the same options?"

"Not common, but not vanishingly rare, either. I've personally met about a dozen outworlders like us. You ending up in the same family as me... Well, that was lucky, but not amazingly so. There are only a few hundred demonic families in existence. As for the options... There's no way to know for sure. You'll have forgotten the other four options that weren't the ones you picked."

... She opens her mouth to protest that she definitely remembers them, they were -

And then she notes that she does not remember them. And she closes her mouth.

In a somewhat small voice, she says, "... I remember my brother picked something different than I did. And he got a - mystery box... thing, once he was done."

"I'm sorry about your brother: we'll have to look for him. As for a 'Mystery Box'... That's intriguing. I've heard of them as a rumour, but I wasn't sure if they really existed."

"It's okay. I can't imagine he would have accepted me getting dragged here without wanting to come with me, and I... remember he made the shadow list things and was very sure about whatever his choice was. ... And he said to match my eye color, that might help. He'll be running around with lilac eyes."

"A non-Lilim with lilac eyes? That should definitely stand out. It shouldn't be too hard to find him once we have the search underway."

Little smile. "Okay, good. Oh - the Augments I picked were the Tome of Gateway, the Tome of Life, the - ethereal one? The one that lets me pick cards, and the consensual body-changing one. I don't know how that fits into what you and assumingly other people have, but ethereal combines well with Gateway."

"I picked the Tome of the Gateway, which is what gave me all these lovely mouths and eyes. The shadows didn't tell me that I could have multiple things, so the rest was picked for me - I got the eyes of forgetting, the summoned armor and shields, the cards, and the aura-reading."

Nod. "I nearly got dinged for stalling when I lost my temper and started yelling at them for being so terrible at explaining anything."