Welcome to the world of MLC and depression! Yes, they do tend to get a bit foggy when it comes to finances and I hate to say this, but you can't rationalize w/them. She's in a fog and thinks that "dad" (you) are going to take care of everything for her.
The best advice I can give you is to make sure you keep an eye on your finances. She's sweet 16 all over again and doesn't care how things are paid and thinks that even after a divorce everything will remain the same....she has absolutely no clue.
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.
