I would venture to say that he is responsible for her since she is living w/him full time.
I have a question, just because I'm curious,...since you are adamant about a divorce from your h, then why did you come to a forum that is suppose to be helping those who are trying to save their marriages? I could see you posting in the Surviving the Big D forum since that is where those who are divorced or getting divorced and not seeking to save their marriages.
or,
Are you hoping that by filing he'll suddenly wake up and return home? Are you using the divorce as a means to try to wake him up?
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.