The spell is spent. It gives her some feedback of not healing anything because there is nothing to heal, but otherwise it worked...

...then there is something in the after-effect of her usual scream, a clarity to it. She can sense the living beings in the house, she would be able to point Scott's direction upstairs and there is a sense that Henry is actually not human, more so than Lydia and Scott.

Henry ducks, covers his ears and manifests his wings to cover himself.

"What was that?"

"My scream. It's usually a little different, though. I could sense Scott and you. Did I break your spell?"

"A little heads up before? And..." Henry manifests his halo.

"Uh, I don't think anything wrong with it, in fact. Apparently it manifested with you scream in an interesting way it lets you... hear better things related to the spell, with a healing spell you can sense living organisms better, I guess if you used, say... a metal-based spell you would be able to detect metals around you."

Where Scott? Is this kinda of screaming usual around Lydia?

"Maybe we should check on Scott. Werewolves tend not to react well to my usual screams."

Henry nods and walks upstairs.

Scott is standing and covering his ears.

"Is it safe?" he shouts.

"Yes. Quite surprising, but safe. Are you okay?"

"Not if she screams again. Banshee screams are painful for us. Is she done?"

"Well, I think she is? Ask her. I have a spell that creates a sound-proof barrier but it might not work against her and it blocks all sounds. Oh, and she is a spell-caster now, it worked."

"That's good. I finished making your bed, so you can stay here. I'll talk to Lydia."

He goes downstairs. 

Henry checks the accomodations then picks one of his own books and starts reading.

Scott returns after a few minutes.

"Me and Lydia are going to talk about what your magic means for our world. You can sleep here tonight, and we'll figure something more permanent in the morning. Sound good?"

"Sure. Is this the kind of discussion you want to have by yourselves? Is Gabe going to be okay over at Stiles? He won't wake up for a few hours, so moving him is going to be hard."

"He'll be fine, the Sheriff won't kick him out just because...well, I don't think he will. We'll check up on them after lunch."

"Good. I'm not all that tired enough and want to adjust to your timezone. So instead of napping I will copy some spells for you."

"Thanks! See you in the morning?"

"See you in the morning."

And the next morning, Scott is making breakfast. 

Who wants crepes? 

Henry would love some crepes. He takes a look over Scott's shoulder.

"Good morning. Those look tasty."

"Here, enjoy." 

Henry gets a plate of fruity ones with cream and another plate of savory ones with cheese. Scott had to be prepared.  

"You are lovely!" Henry says before digging in.

He sits down as well, sticking to savory.

"Lydia went home as soon as you went to sleep, but we'll go over magic later. What kind of things will she be able to do? I think she'll probably be better at it than I am."

"You mean with normal magic or the scream and spellcasting combo?" Henry asks between bites. "The latter will mainly sharpen her ability to sense things."

"Let's hear about generally too. Will she be better at learning some spells than others?"  

"The main factor is the ability to memorize things, which can be quite a time investment if you use the spells often. I would recommend having each one of you having all spells memorized and then maybe someone with free time or disposition can be your main caster," he shrugs, "why did you suggest Lydia in particular?"