You do not have to do what she expects. So, best advice I can give right now is don't. If you want to do the work STOP at five hours. Or if you don't, STOP. I think seesaw has the right idea. You can be a friend, or do some work to earn some money, don't do both. And, if she doesn't treat you well, let her know, walk away, do what is good for you...you don't have to be rude but you do have to be clear about your limits. This is a relationship that may not be worth continuing....or you may just need to step back for a while. If it is hard for you to speak up, you could write her a note/letter, gives her time to read and think about it (not in your presence) and respond.