Crazy MIL

So I think I got most of them. My husband is in the middle of a nasty custody battle and we live 4hours from his mom. We drive 4hours every other weekend to get his kids from their mom. His mom seems to think his kids are hers. She gets to see them and say hi almost everytime we get them from their moms. She makes no effort to come down to our house and see them. She expects my husband to meet her half way when we already spend so much money on gas and give them to their mom. Which the oldest child is in school. His mom wanted the kids for spring break and I said no because if anything happens to the kids we will be at blame and their mother has already been trying to put blame on us for stuff we didnt do. Plus we plan on spending easter and doing stuff as a family. I'm currently pregnant and the last time I was she cussed me out like this and I had a miscarriage. I feel bad but I'm seriously done with her and I literally hate her guts. I really want her to be no part in this babies life. She literally cussed me out for trying to talk like adults their was more then just this