That's so frustrating when you do the right thing and take them to the vet and then the vet can't find anything wrong, yet you know something isn't right. I'd give her a good feel; really check her over and test that leg that you think might be the problem. When I read Callie's post about the possibility of an intestinal kink, that somehow clicked w/me. My Puddy, also a calico, had problems w/that and it caused her incredible pain, except that she cried relentlessly until the problem was fixed. I guess all you can do is keep an eye on her, test that leg, and palpate her abdomen to see if you can feel anything unusual and if she cries when you do any of it, get her back in to the vet. Sorry not to be of more help.