children photos on social media

Hi all! Just looking for some help or advice, this app is the only form of social media I have, no Facebook or twitter or anything. I have two young children and in the past my aunt who has Facebook told me that she saw the lovely photos of my children on my MILS and SILS account. I googled and sure enough their facebooks are plastered with photos of my children like the cover photos and everything so I kindly informed them that I was not comfortable with the kids photos on social media and if they could please remove them, they told me they did and now fast forward again a few months past my aunt told me there was more on there and this time they not only kept the original photos but they have continued to add more to it. How do I approach this? Should I ask my husband to handle it this time? I don't want to hurt anyone's feelings but I don't see the need to put my children's photos all over their Facebook