I don't think your being a bitch- I think your just frustrated that I'm guessing you gave a month to help them find care and then turn around and not return the favor. Reason why you should keep things professional and by your contract....I learned the hard way too
I agree with the ladies- if it's in your contract then you need to follow it. Just end it as I think Cocoon is right, she probably doesn't think it's fair that you terminated and she might start getting more nasty
Good luck