First, you have to find out that why she is behaving in a negative way. There are few possibilities. She might be under the pressure of her family. She herself might have lost the hope and accepted her fate. She might be depressed (suffering from Depression). You should ask her about this. You should show your willingness to meet her parents (you can discuss your future plan with them even though you do not have job at present) or suggest her to create mediator, whom she can trust. If nothing works out, prepare yourself to accept the reality.