If she does a control bite to check, yes, it's faster, but it's not dramatic.

And if she starts biting herself while touching the rock, does that have any perceptible effects?

Nothing obvious while she's biting, but the bite heals when she lets go.

Kind of hard to do much more science without getting herself ill or injured. She emails Bella again:

I have a healing rock that should heal any person who touches it; it works as far as I've been able and willing to test it, which isn't much. Do you know anyone who knows about magic and is currently sick or has a minor allergy or anything?

Not personally, and you'd have an easier time than me advertising in the Avalon.

True enough. I'll put out a flyer.

I wonder if I'll get more takers if I offer it free like a clinical study, or charge enough to look confident. Maybe I'll go with "you only pay if it works".

It's probably the most independently enticing scheme but try not to sound too... infomercialy.

Yeah. Getting the tone right on a one-page lamppost ad might be the hardest part of this.

She attaches a draft of a flyer like the ones she's seen around the Avalon, nicely formatted and reading:

Magic Healing

Illnesses and Injuries

Price: $200 if it cures you, free if it doesn't

Email [this address] to make an appointment.

It only takes five hours for the first email to come in. do you only do critters

I can do anyone who knows about magic. I can theoretically make appointments outside the Avalon but it would be better to do it inside if the patient can get there.

what if they're like unconscious so they won't see anything

It's important that nobody else see anything either, but I have hope we can work something out if you tell me the details.

my grandma had a stroke and she's in hospice

Oh dear, poor both of them.

So first of all, I want to make clear that I don't know if the magic I've got will work on a stroke. It's possible that there won't be anything I can do. It sounds like you can't easily bring her somewhere else; if you go visit and bring me in with you I can try it there.

I can do that

Then from there it's just a matter of scheduling and location, assuming her hospice is accessible via the bus network.

It's not right on a line, but it's only five blocks away at the far end.

(Meanwhile, she gets more emails - injured manticore, diabetic bohemian lion, pregnant human-but-in-the-know who wants to know if she can fix various pregnancy-related complaints, nokk asking if his dad could stop going crazy in the manner of nokks.)

Everyone who can be in the Avalon on Saturday gets an appointment in the Avalon on Saturday, with the options being the park or, if they live there, their house. The Nokk gets the same pessimistic warning the grandkid got, and the pregnant human gets told that she doesn't have any experience with pregnancy and that this is at her own risk. 

Now that she thinks about it, this is the kind of situation where people make each other sign release of liability waivers. She goes online and prints off some copies of a boilerplate one like the ones she's seen on field trips and summer camps, then takes a look at the critter internet for anything on critters suing each other.

Critters can sue each other through the normal court system via a law firm that will cooperate with obfuscating any crittery details, including excusing the absences of monsters.

That's better than a whole second court system. She sends Bella a list of the ailments she's going to get to try to fix, leaving out any patient details and mentioning her doubts regarding the age-related diseases and the pregnancy.

The nokk thing almost has to be a magical problem, nixies are females of the same species and don't get it. Age-related disease doesn't seem like it should be unaddressable with magic, since some critters live much longer than humans. No idea on the pregnancy.

Yeah, aging really seems like it should be doable in principle. I just don't know if what I've got now will work on it. I'll see how things go with the stroke patient, I guess.

Stroke is mostly brain damage, do you have any data on how your spell handles that?

Not a clue. I haven't had access to anybody with brain damage, and it's a hard thing to test on animals.

For lack of subjects? Or you don't think the results would be clear?