I actually don't find it realistic that somehow Jimmy is able to hide going to law school and taking the bar 3x from Chuck and the entire HHM (including Kim?). But ok I'll bite.
I also don't find it realistic that Jimmy does hide going to law school and taking the bar 3x from Chuck and the entire HHM. Plus I think of those cases where employers will actually loan employees money to take classes. I think was kinda the case with Kim Wexler.
Question: Why? Pride? Embarrassment / Shame?
Actually I also have tutored my younger sibling in maths all the time before when e was an engineering student. I think it would be very beneficial to ask your relatives for help in subjects you're taking that they've taken before. I don't see it as realistic that you go to law school but don't ask your own older sibling for any kind of help whatsoever from Day 1.