I had a similar experience with my ex-mother-in-law with my first born (he’s now 24). In her case, her first born son had passed away at birth. She would call my son by her deceased sons name, would make comments about how she knew he would come back to her, and was caught attempting to breastfeed him. I know some grandparents can be overbearing, but this is obviously not normal behavior. I’m my case, she even contacted CPS stating she needed to adopt my son because she could take better care of him. My husband and I had to limit contact with her, and only allow supervised visits with one of us present. I hope you are able to find a better resolution in your situation. I don’t have any real advice, but wanted you to know you are not alone.