Whoops! Don't strain yourself, kiddo. You're quiet enough as it is, wouldn't want you to lose your voice.

[Seems as if the placid cuddling isn't enough, though, so Lup draws back a few inches to lift her hands and begin brushing gently through the girl's hair in a way she hopes will be soothing.]

The trick of Polymorph is holding on to who you are while you're doing it. You don't want to turn into something and then forget how to be a person.