(Her book warns that most attempts at creating species, especially combining two disparate animal lineages like mice and sparrows, result in a much higher rate of birth defects than was present in either group previously, even when the researcher does everything perfectly.) 

Leareth is always happy to take a break from his own work and do the mage-work parts of putting together more sparrowmice.

It's fun. She's working in parallel on other stuff that will be more directly applicable to turning a monkey into something that looks more like a human - the result isn't aesthetic at all on mice but she does want to practice getting them to be furless and have long hair on their heads for this reason.

It's really not aesthetic at all! Amshalan thinks it's absolutely hilarious, though. She really enjoys watching the sparrowmice, and all of the various results, through Belrun's eyes. 

The first batch of imported monkeys turn up. Leareth had an entire new cellar area excavated and added to the building, so they can have lots of space. They've got toys to play with too. His people who went south to buy monkeys weren't able to find a convenient species that was both anywhere close to human size and also non-aggressive and practical to keep in captivity, so these are still fairly small monkeys, but Leareth points out that changing a species' size is, per the book, one of the easiest things to do. It can be done without magic, even, dogs have been bred into all sorts of different sizes. 

All right, she will try gigantifying some mice.

The first few tries tend to come out with very odd proportions but it is, in fact, very easy to gigantify mice. 

Well, she'll fiddle with proportions too, she doesn't want monkey-length arms or toes.

:It'd be kind of neat to have feet that could work as hands, though?: Amshalan points out. :Extra hands. Make up for my lack of any hands. And you could still put shoes on if you didn't want people to notice: 

:I'd have to get custom shoes, and monkeys don't actually walk on their feet, much, they get around in ways that involve all their limbs more, so I'm not sure it'd actually be comfortable:

:Oh, that's true. Still think it'd be neat to be able to climb like monkeys can, but - I guess if you have wings it's not as practical anyway, and also you won't actually want to live in a tree: 

Fiddling with exact proportions and then making it heritable is also pretty straightforward. 

The winged baby mice are in general developing more slowly and taking longer to reach maturity than normal mice litters, but their feathers are mostly in and they're starting to flap about the cage.  

Adorable.

Once she has a breeding population of her most interesting mouse strains she falls back to working on infectious disease research with much of her available energy and just looks in on the mice occasionally and teaches the friendliest winged ones tricks.

Leareth grows some more! He's nearly her height, now. His voice is usually deeper, now, rather than cracking at random. His face still looks very young, though, it seems to be out of pace with the rest of him, or maybe it's just that fourteen-year-olds look reasonably grown up when you're yourself fourteen, but like babies when you're twenty-three. 

She starts working on the monkeys, trying to figure out how to adjust their faces so they look like - different monkeys, to begin with, she doesn't want them to be rejected by their cagemates, they're social animals.

The monkeys are more interesting to spend a lot of time with than the mice, just because they have personalities and clear likes and dislikes as individuals. Now that she's had the practice with mice, it's quite straightforward to change their faces. The monkeys find this confusing! But they adjust quickly. 

Ideally she'd like to be able to do it without it hurting them, since ultimately she does maybe want to fiddle with Leareth's eye color and such.

She can pretty easily get to the point of doing it skillfully enough that there's no uncomfortable recovery; it's still nicer for the monkeys if they're anesthetized while she's actually molding their facial bones and cartilage into a new shape. (Also, it's hard to coax an awake monkey to hold still while she gets her Sight properly situated.) 

Her book doesn't actually have any instructions for modifying eye colour, but it's not hugely different in principle from changing other pigmentation like fur, and if she spends some time studying the structure of eyes very closely, she can figure it out easily enough. It's also noninvasive enough that the monkeys can handle it fine awake, though if she wants to do it that way she'll need someone to hold their heads still for her. 

She's mostly interested in how squirmy various interventions make the monkeys for the applicability to whether Leareth will need to be unconscious; there's no real reason not to have them out for practice once she has that information.

Leareth thinks that he'll be much better at holding still than monkeys even if it's a little uncomfortable. He dislikes the idea of being made unconscious - not nearly as much as she hates Mindhealing, but it's a not dissimilar shape of dislike. He'll trust her to do it if she thinks it's best, though. 

"Ideally you'd be awake both for that reason and so I don't have to learn to do a meld with a different person."

"Very reasonable!" 

"I think you'll be fine with some painkillers if I work in small increments, though, which I'd want to do anyway, because unlike eventually giving some unfortunate monkey my face where I'll have a mirror, I'll be working off memory."

"That makes sense. Is it going to make a big difference to you, that my eyes are the same colour as before?" 

"It's not so much any one thing as the gestalt but that bit I'm particularly confident I can get right without a reference closer to hand than 'saw you in a dream the night before'."