Well, there are two likely possibilities:
She signs and therefore they will probably provide an interpreter for her (would that person live with the tribe? sleep there? participate in challenges?)
Or she lip reads which means she will have to be close and facing anyone speaking to her. On the other hand it would be good for seeing what people on the other side of camp are talking about!
Hmmmm, this is very interesting and I can't wait to see how it plays out. One thing I know - my mom is deaf and they are stubborn, tenacious people! Something that could work to Christy's advantage if she posesses these traits.