limping

My cat is not walking on her right hind leg and when she sits down she holds it at an angle.we let her outside and she was fine but when she came back in I noticed she was limping.I don't know what she did to it.

Your cat likely has a leg injury of some sort. Members of TCS can't diagnose your cat online. You need to take your cat to the vet for treatment. I know it's Sunday and many vets are closed but give your vet a call anyways and the after hours voice mail message (hopefully there is one) will have info on what to do for emergencies. You can aslo use this directory to find a local vet ER: http://www.veccs.org/index.php?option=com_hospitals&nationid=1&Itemid=193 All pet owners need to know where the nearest vet ER is or, if there isn't one, how  the vet handles after hours emergencies.