Her stool may have been soft because her system is still recovering. Typically chicken or any type of pure protein will make it firmer. Overfeeding can also cause loose stools, although that wouldn't be the case here.
If the stool continues to be loose, I would follow up with your regular vet.
Maybe go easy on the new food and indulge her on the chicken if she still wants that. Whichever, don't worry if her appetite doesn't fully return today or tomorrow. She has been through a lot.
I hope she likes the Fromm and that it works well for her.
