AITA For blocking my mother from my daughter's Facebook account

My mother and I have always had a strained relationship but I try to keep that from affecting the relationship she has with my kids. She is always overstepping her bounds when it comes to the rare occasions she interacts with my kids but I still try to encourage them to have a relationship and keep from them the bad history we've had. For reference sake, my daughter is 13 and my son is 11. I told my mother a couple months before her 7th birthday that I wanted to get her ears pierced for her present. A couple weeks later, she asked my daughter (MD) while in walmart if she wanted get her ears pierced. I let her do it because MD wanted it and I still had time to figure something else out. Christmas comes around, I tell her I wanted to get MD a doll house. A week later, she calls me telling me she bought her a doll house. Lesson learned, I stopped telling her what I planned on buying the kids. Years later, the kids now have their own tablets and she friends MD on facebook. She messaged MD one day asking if she can come over. She was about 12 at that time so definitely not able to make that decision. I've never stopped her from coming over. I just want notice as I would ask of any visitors. I feel that's common courtesy. Today, she's messaged MD with an account she created in MD's name with her listed as the parent to join up on Facebook messenger for kids. I had no knowledge of this. Final straw, I blocked her from her Facebook and texted her asking what she was doing. I'm still waiting for her response. via /r/AmItheAsshole https://ift.tt/346rD1E