roommate problems?

So 2 years ago I got an apartment by campus and my best friend moved in. Well, I got pregnant in August and married in November so clearly we've been talking about options. She finally decided (after back and forth and randomly packing and unpacking) that she would move out this May. I'm due May 8th, so we've tried to have the discussions of her leaving earlier so that we can get ready for the baby. And it's not like we'd be kicking her out or anything, her boyfriend has his own house that she said she'd be moving into. But now she's telling me she won't be moving until the week after the baby's born, and we can't do anything about it because we are all mutual signers in the lease. Now I'm trying to separate my hormonal anger from what a rational reaction to this all would be