MIL highly involved with husbands ex

My husband and I have been together for almost 10 years. The first two years we were dating/engaged his mom use to tell me he would have married and loved his ex, we’ll call when Kathy, if it wasn’t for the girl before her breaking is heart, we’ll call her Joan.

I ignored it mostly and just let her have her thoughts on who he should have been with because she was still very nice to me.

But the past few years her and my FIL almost never see my kids unless we make the effort, and the never text or FaceTime them unless we do so first.

We eventually just stopped mainly because of covid and our child is high risk. But we were tired of always having to put in 100% for them to be involved and them do nothing.

I will text them pics and videos of the kids and never get a single response back. I post pics on fb and they ever like or acknowledge them at all.

But my MIL is very involved with his ex still even though they barely dated a year a decade ago and he almost never even brought Kathy around his family so it’s not like they got close to her. She is always liking pics of her kids, commenting and telling her what a good mom she is, even buys them birthday and Christmas presents and makes their bday cakes for free.

Am I wrong for being hurt by this? I’ve never said anything and don’t intend to. It just really hurts to see her be so involved with someone else’s kids and barely give her son’s kids the time of day.

I should add what makes it even more weird is my husbands family is really close and they adored my husband to the point my SIL cosbnrslt said she was jealous he was the favorite but once we had kids that changed for some reason. They’re even very close and involved with my SIL’s kids.

Their excuse for that one is they know we can take care of ourselves and she needs more helps even though she’s grown, lives on her own, and is married.