I can see a preference for single character first person narratives and autobiographies coming from an authentic source, but in other work, wouldn't you leave a bit of room for someone getting into the heads of various characters, including deaf characters? We'd have lost a whole lot of great literature if writers had to make every character he or she created and dipped into a facsimile of himself or herself.
I'm trying to imagine one of Faulkner's contemporaries advising him not to write the Sound and the Fury because he (Faulkner) was not mentally disabled, or Dickens discouraged from writing Bleak House because he was a man / Edith Wharton told to leave Ethan Frome to the guys.
In this case, the writer may not even be writing from the deaf girl's perspective, just wanting some more accuracy on what her situation might be.
