My baby's grandmother is a B***h

Since the moment I met my ex's mom she had disrespected me to my face. She told me I was a horrible person for having my 1st son so young, she said that I must have gotten help from my parents "which I didn't" she has told me to my face how I was raised poor, on public assistance and so much more "too much to type" these are all things said to me to MY FACE. She has told her son when we were together I was just using him "which I had 2-3 jobs and paid my own bills and got HIM a car" she's just numeruously disrespected me. Now that he and I are broken up and I am pregnant with his baby, the lovely "visiting grandma" or allowing her in the hospital had been brought up. The way this woman has treated me I want her NO WHERE NEAR ME OR MY BABY. Am I wrong for this? I really don't know what to do....I feel like maybe just maybe I should allow her to visit in the hospital but I really don't want her anywhere near me or my family. I don't feel obligated her son and I aren't together and I really don't see why I should even allow her around my kids and I....