Grandma not allowed around my kids

I've decided my grandmother is no longer allowed around my son's. Especially my oldest. I'm currently in the hospital because I just had my baby and I left my son's in the care of my mother and my grandmother. So my mother is staying with me tonight and she told me that yesterday she got really angry at my grandmother. My grandmother has zero patience. ZERO. Yells at the slightest of sound. So my mom tells me they were eating dinner and my eldest he's on the spectrum, he is not great at social ques, all my family understands this except for her. They were talking and my eldest was trying to tell them something but didn't say excuse me so she yelled at him so loudly that he got startled enough to where he fell backwards off of the bench and all of his food fell on top of him. My mother said she got so angry at my grandmother and asked her what her problem was. To look at what she did because she's always yelling for something stupid and small. That pissed me off enough hearing that. Today my son's came to visit me and my eldest was so excited to see me and show me the rose he bought for me. Right away she tells him to be quiet and his face drops and his smile faded away. That boiled my fucking blood. So I ignored her and told him to keep showing me what he got and he got his smile back and gave me the rose. Then he started singing happy birthday to his baby brother and again she starts shushing. I again told him to keep singing and ignore her. When they left I told my mom she's not allowed to be around my kids anymore. I'm not going to tolerate them being told to be quiet for literally fucking speaking. I'M the mother. ME. I will tell them when I think they're being too loud. I will scold them when I feel it's necessary but what she's doing is not necessary and other people are starting to notice it. My mom's roommate even told her to calm down because my son's weren't even being rowdy and she was already yelling for them to be quiet while playing with fucking blocks. So I told my mom they're not allowed over anymore because I'm not going to tolerate it and my mother told me she told my grandma that if she loses out on seeing her grandkids because of how she's acting she's free to leave. My grandmother was supposed to help me the week I go back home and I told her no thank you. I'm not going to hear her screeching voice yell about the smallest things that don't need to be yelled about while I'm home with a new baby and trying to recover. Not only that but when I FaceTime my son's and they were with her you can tell the difference of their mood. They were quiet, not wanting to talk to me much. Once I FaceTimed them when they were home with my husband they were giddy and laughing and being silly. So as a mom it's my job to take my kids out of toxic environments and that's what I'm doing and I'm not gonna feel bad about it.