Social Media Privacy for Children/Babies

SO and I do not have social media platforms like Facebook or Instagram. We dont share photos online regularily, and tend to only share them when visiting family and friends in person or via text. My MIL is big on photosharing on her FB and Insta to everyone and anyone. Recently had sent her a photo of my baby bump through text, and my SO was pissed when he found out that shr had taken it and put it on her platforms, without asking me. I didnt think much of it, but he hates that my privacy was infringed upon since I was never asked if she could share it. We

think it is sweet she is a proud grandma to be, but it brought up the question of if we want her plastering hundreds of photos of our baby/kids on there in yhe future without our permission. Are we being too protective?