DEAR ABBY: My adult son has a drug addiction, for which he is receiving treatment. My family and I have just met his daughter, who we had only recently learned about. She's 6. I had a celebration for her birthday at my house. My mom (the great-grandma) took pictures of the birthday girl and her friends, and posted them on social media. I had asked her before the party started to please not post pictures of the children on social media. She said she does what she wants.
I don't believe pictures of children under 18 should be posted on social media and, in this case, especially since we just met my granddaughter. She didn't have permission from the other children's moms to post. I feel my mother disrespected my house and my rules, and I need to know how to handle future events. Please help.