Monster-in-law!!

So, my MIL is really a nice person but she speaks her mind, and she hates me. She has told me how she wished my husband of 4 years would leave me, and the only I was still with him was because of my kids, not to mention when I was pregnant with my first she set my husband up on a date with another woman and he was seeing her behind my back, he almost left me while I was pregnant and we were married for this woman. Well now I'm pregnant with my third and we moved to Carolina, she lives next door. 😒 but she will not let me buy a single for my son, I'm 24 weeks and she keeps saying if I buy something it's going to jinx it. My husband is a mommy's boy so he listens to her and won't let me buy anything. Any advice?