Help! how do i stop an annoying friend?

She's driving me absolutely crazy! She expects me to text her constantly, hang out with her and her family EVERY weekend, gets mad when she finds out that I went and hung out with friends with out her that she don't even know these people nor do they know her, not to mention when she has a couple of drinks her language becomes extremely vulgar and she repeats herself constantly, asks question after question about every aspect of my buisness constantly. On top of all that I work full time have two kids and a home to take care of and she gets mad when I don't text her back immediately. Omg. If things couldn't get worse she's my babysitter...yeah! Seriously. So how do I handle the behavior and not loose my babysitter??