It seems to me one of the adult hens has jumped off the perch and landed on her. There's no obvious open wounds but she looks almost splay legged. She can't support her own body weight, though still seems quite lively at the moment.
Hello there,
My first Faverolle hatched yesterday, just thought I'd share a pic of the cutie :)
Of course, being that it is the only one of our dozen eggs to hatch, I'm convinced it's a roo and have called it Fabio, haha