My future mother in law is a bully and controls my fiance?

She totally controls my fiance, and she(my fiance) is scared of her wrath. I want my fiance to answer for herself, and her heart. It's really putting a pinch on our relationship. In addition, my fiance broke up with me, but we have reconciled. However, she's afraid to tell her mom/family, for fear of persecution. We both have our own homes and share a brand new baby together. Her mom, says that we need time apart. nether one of us want that, but my mother in law is in her ear 24/7 about being solo. She loves me and wants me around, but mom knows NO boundries!