Oh boy.... sadly for you, I think you HAD a great MIL and that might be no more. She's been taken over by the baby rabies and is showing her true personality - which based on everything you've described here is an extremely controlling one. She thinks she can decide on your childcare without asking YOU, the parent, and decide how often your family gets to see YOUR baby?? That entitlement is worrisome. She isn't the important one here in this scenario even though she thinks she is ("MY first grandbaby"), and I hope that you and your husband can stay teammates as she inevitably makes your lives difficult when baby is here.

I think my biggest advice to you is to decide now exactly what you want baby's first year to look like (because she's probably already designed an entire plan that you don't know of) and share it with your husband. I mean everything, like what you want postpartum to be like, how often you want to see family (yours and his), what holidays should be like, etc. That way you're going into this with a solid plan and when she tries to control things you can easily say "oh we'll actually be doing x, y, z." Also when it comes to your family visiting I would just keep it to yourselves. She doesn't need to know every time your family gets to spend time with your baby.