Social media MIL...

80% disgusting 20% beautiful

Hello, I'd just like to give a bit of back story I'm 18, my boyfriend is 22 we've been together 2 years, and we live about 200 miles away, I've only met his mum once or twice because of the distance and them not getting along all that well but she's never been that fond of me because I'm young which is completely understandable but I am actually a decent person lol so wish she'd give me a chance. But I saw her a few months and we had a good chat for the first time which was lovely, afterwards I added her on Facebook and she accepted and followed my insta and I followed back, and I thought that was really nice cause when I add someone on Facebook it's a friendly gesture. But since she's been FB friends with me and I've been on her insta she's been posting loads of photos of him, with captions like 'Family is best- I love my family!!!' Which is all okay. But she also posted a photo of me and him on his last birthday when he was staying with me and CROPPED ME OUT?! I told my bf cause it was a bit upsetting- she could've just posted a photo of just him not go through the effort of taking me out of it. He told her that he was upset she posted it without me cause he was irritated too and now she's changed her FB profile picture to a picture of him sat on he sofa, it's like a really relaxed photo with his shirt up and you can see his belly and pants above his trousers, even I don't post photos that casual and now she's got it as her pp?! As well as other posts of him telling him to keep strong etc which is great I mean FB is for bragging about your kids isn't it really lol but It's a bit odd cause they've never really liked each other but now she's trying to prove how close they are and how much she loves him, because I'm on her profile. I'm not really sure how to approach the situation? Should I make more of an effort with her because I'm not an enemy, or should I leave her to it and just let her get past her son being in his first relationship that's getting serious. Or should I be open with her and say you upset me because you cropped me out of a photo and are now having him as your profile pic despite not actually liking each other?!?! Please advise I always hoped I wouldn't have a bad MIL situation haha