Dear Ann, 

There are two sides to the story that need to be considered: the physical limitation in itself, and the group the person is interested in. Some physical limitations (such as partial deafness, a type of diabetes, the effects of polio...) are not in themselves impediments for a vocation, so it is quite possible that most convents would accept a candidate with these, providing everything else was in order. Certain congregations though, because of the nature of the work their sisters do, have their own standards as regards physical heath. Some groups may accept candidates that most others wouldn't (because of their individual charism and apostolate) while on the other hand there are some that could not accept candidates with limitations that in most other groups would not matter. Sorry for such a general answer, but you would need to get in touch with individual groups. The first ones you go to would most probably be able to give you a more specific answer, once they understand what limitations you are talking about.