My mom hates my kids...

Long story short. My mom has never been a mother figure. My grandparents raised my brother and I and she was too busy chasing men. So I’m 32 years old and have a family now and my mom has never really been a grandmother to them. I’ve tried working and her watch them but that only lasts 2 weeks and tells me she can’t do it anymore. I can tell my mom has never really liked my kids especially my youngest which is 4. He’ll be playing running around like any 4 year old does. And she’ll have a look on her face like she is bothered by him. This really bothers me and I’m starting to dislike my mom for it. Any suggestions? I’ve said to her if they bother her she of course says no. But I know she’s lying.