Mothers-in-law tend to get an unfair bad rap, but in this case, I think yours is going a little overboard.
Some of these things, you just need to let slide right off. Take breast feeding, for instance. You have stated your intentions. You can be done with that. No formula and no bottles in your house, then Grammy won't be feeding the baby, will she.
My sister, who I love very, very much tends to get pushy when she's excited about something. It's a miracle I got pregnant after being told I could have no more kids. When I found out my baby was a boy, my husband and I immediately agreed on a name. She informed me she would be calling him something else.
I said, "Excuse me? Why would you do that? How about just calling him by his name?"
It peeved me, for sure. But, in the end, she called my son by his given name and it turned out to be a non-issue once the baby arrived.
You have every right to tell your MIL that you feel like she thinks you are nothing more than a baby incubator.
If she's sarcastic, as am I, I would probably fight fire with fire.
"My baby... my body. Maybe I'll just decide to hold the baby in".
When I was very close to the end of my first pregnancy, my own mother drove me nuts. She didn't overstep boundaries or try to tell me how to mother my child. However, I had a high risk pregnancy and she came every day to check on me. I remember crying every time I heard her pull up. I was kind of mean. My daughter's father worked many hours away and if it weren't for my mom dragging me to the hospital 45 minutes away when my contractions were a minute apart, I could have given birth at home all alone which I didn't want. But, I didn't want to go to the hospital either.
She was there with me through all of it and dad barely made it in time for the birth. Looking back, I'm thankful for her.
When you are pregnant, I think it's perfectly okay to say things like, "I know you are excited and I know you are thinking of this through the eyes of a mother of a son and you are so thrilled. However, it hurts me when you say or do things that make me feel like I basically have nothing to do with it other than giving birth to your grandchild. This is MY baby too. This is MY baby, first and foremost as I am the one carrying it. Please understand that the love you have for your son is the same love I will have for my own baby and I need you to respect that. Please. I love and respect you. I understand that all kinds of feelings are flooding in because you loved your own baby so much. Please allow me to have that for myself as a new mother. Please allow me to make my own choices and figure my own baby out for myself.
You'll be a wonderful Grammy if you give me a chance to be a wonderful Mommy on my own. I may ask your advice, I may even need you, but please, let me figure it out for myself. You're a mother and I respect that.
Now, I need you to respect that for ME, because I have a baby coming. MY baby".
Some of the things she's said and done seem totally unfair.
You have a great relationship otherwise, so you can stear things back into perspective. It's not about confrontation and your husband should be backing you up.
The first bond babies have is with their mothers. Your MIL can't change that.
Have your birthing plan, your breastfeeding plan, your sleeping plan, your figuring out your baby plan in place and just do what you need to do.
Your MIL will figure out that she is not the center of the universe when it comes to your family and new baby.
I wish you the very best. Let us know when the baby arrives.
:)