Movie was about a young girl whose parents are having problems. She spies on them with the help of a neighbor boy. Her dad sneaks back home in the mornings so as to appear there is no problem. She keeps track of his comings and goings in a notebook. The boy tells her when they ask her to pick a restaurant for dinner, she should pick one she dislikes because they will be telling her they are getting divorced and then she will not want to go back there. that’s how he came to hate his favorite restaurant.
I think it is the 1984 movie remake of Sentimental Journey. There is little information about it on the IMDb, but the TCM plot summary, brief as it is, suggests it does a gender switch on the original 1946 plot where the child bonds with the mother instead of the father and the mother dies. Your description got my attention because the father in the 1946 version was named Bill, but that is not his name in the credits for the remake. If you can find a way to watch it I’m pretty sure you’ll find that’s it.
“Rich Kids”(1979)
http://www.imdb.com/title/tt0079806/?ref_=kw_li_tt
You can watch it in two parts on dailymotion, here is the link to part 1:
http://www.dailymotion.com/video/x4dsvpw
I put my answer on the wrong one. It was intended for the one after this. NOw I have to paste it and put it on the right one.