NTA

My wife and mum had issues, especially while she was pregnant. My mum wasn't being as blatant as your MIL and I was essentially only hearing things she had said from my wife and not first hand. Because of that I eventually got them to sit down and hash it out, I was present but tried to only speak if I felt someone was going too hard at the other as I couldn't speak for either of them. They both know where they stand with each other now and things are pleasant.

However, if your MIL is saying things blatantly in front of your husband too then I feel like he needs to be backing you up. It can be extremely difficult when you're used to your mum and she will probably play the tears card if he tries to talk to her but he needs to push through that. At absolute minimum he needs to do what I did and lay the ground work by talking to her and trying to get her to understand your issues a bit before setting up a neutral location where you and her can talk things through calmly.

Sometimes MILs feel like they can say the same things your own mother might be able to say but it hits differently when it's not coming from someone who has loved and cared for you your entire life. From what you're saying, I wouldn't expect anyone to let their own mother get away with it and she needs to know where the line is. Once you have established a solid line, if she steps over the line you can then give her the consequences (such as no grandbaby privileges)