I haven't looked into any of the financial aid stuff (need to actually apply first), but I'm in a very similar situation with my parents so I'd be interested if any prior applicants or people that have already applied this cycle have more info.
No, don't ask them. It's not the right kind of relationship for an LOR. I get that your parents are well-meaning, but you may want to send them an admissions article on choosing recommenders to help them understand.