Farmville addiction gotten out of hand?! Help!?

Hi everyone. My mother has been playing Farmville for quite some time. At first she only played for an hour or so at a time, but now 2 years later, she's playing it all day. I am homeschooled, and I have not done any school for two weeks because my mom is playing Farmville. I mean, I get food and there's always a jug of good milk in the fridge but my testing is in two weeks. If I don't get back to doing my schoolwork I'm going to have to go to school, and I REALLY don't want to do that. I also never spend any time with her and I can't even talk to her when she's playing Farmville because she yells at me; saying "I'M CONCENTRATING! SHUT UP!" What do I do to get her to stop playing Farmville? I have had thoughts of logging on to her Facebook account (I know her pword), deleting her farm and blocking the page so she can't make another one, but I would feel so guilty. Is there a way I can convince her to delete her farm and not go back on? If so, how? Thanks in advance.