WOW! That's a horrible experience to have happen in this time of grief. I'm really sorry for you. For what it's worth, I would let a little time pass and then discuss the matter with her personally with your DH there but you doing the talking. It may be important for her to see that you are strong and have very definite plans to protect your life and your marriage. It is also quite helpful for a mother to see her son support the woman he chose to share his life with. It may garner more respect for you. I've seen the man get a little caught between the two women in his life and it seems like a very uncomfortable situation as he loves you both and you both are wanting to show your love for him. I find that sometimes that makes them a bit mushy and not so to the point.
If some time has passed, the hormones have subsided a bit, the possible anger from the grief and disappointment has settled and you have some time to think about the outcome you want for your future relationship with your MIL -- I would have a little breakfast table meeting. You can hopefully empathize with one another in your desires which seem to be similar -- the creation of your baby, the expansion of the family and your support of your husband. I can say that w/ my first miscarriage, I thought I was the one that had it the hardest (I'm not saying you're the same as me :) ... just an example.) I came to find, with my recent second miscarriage, that my DH was crushed but it was based upon my being crushed. Apparently it's hard for them to not be able to protect their lovely ladies from hard times that make them cry. So this time, I handled it a bit different in front of him and he responded a lot differently. (Perhaps this part is neither here nor there!)
Final thought is that at the end of the say, most ladies are programmed for building community and family. And a personal talk can generally get you there faster b/c you will most likely find a common understanding. That's been my experience. (Not to say I haven't EXPLODED at a few people from time to time!!!)
I am glad he is with you on it and you will be talking to her together. Do your best to keep your cool until then. :)
Thanks for your support! My husband stands behind me on this and he has mentioned maybe we discuss this together in a month or so. Meaning we would talk to her as a couple. My husband has talked to her in the past, it usually gets better but you can't teach an old dog new tricks. This is probably the angriest I've ever been with her, most of the time I've brushed it off. But with adoption and possibly donor eggs in the future I may be on edge with inappropriate comments
I am sorry for what you are going through and it is not fair for her to be making it more difficult for you. That being said I had said issues with my ex MIL, asked ex husband to get involved and say something to her so maybe she would back off. He refused and her taunting became so bad I went off on her and told her where to go ( I couldn't hold it in anymore). It got better in the respect that I no longer had to talk to her but it sure made things worse for my ex. I don't recommend going in the direction I did. I would wait until the timing is a little better and ask your DH to speak to her, if he does not want to then try talking to her in a nice, calm, adult manner (not as I did, lol). Whatever you do, do not let it build up inside of you and do not let her continue to disrespect you.