I guess I just don't see ICA as being jealous. I just see her as being selfish. I think she was ticked off that her parents were actually making her step up to the plate. I think she hated the fact that they questioned her about where she was going and with whom, when will you return, how are you paying for that? and so on and so forth. She did not like to be questioned. And , if her parents caught her in a lie... it was their fault that she had to lie. I think that has always been happening.
She sees herself in a whole different life, well we all know that. I've said this a few times before on other threads, She knew how to play her parents against eachother. GA would have taken care of all this crap a long time ago but CA wanted to tip toe around it, that is until she had enough. Then she would take care of it herself. That is why GA looks like the bad guy IMO. He was used to CA taking over. I would bet he didn't know half the stuff that went on in that house because they did keep it quiet. They kept it quiet because CA knew how to handle it "better". He didn't know about anything until it was bad.
IMO CA kept things from him because she over sympathized with ICA. I've seen women do this and it is so bad on the family and marriage. The dad ends up being the bad guy and he doesn't even know about it. Kinda... "wait till your father gets home" or " if your dad knew this" kind of thing.
Sigh,,,,there I go on my rant again. Sorry folks.