Partner's mum is driving me insane😫

My son is 8 weeks old and my partner's mum is doing my absolute head in, her house is very messy and she smokes in her house, my partner told her to tidy up and not smoke in the house when my son is coming over to visit, every time i've been round since him saying that, the house is a mess and it's stinking of smoke. She also never sees my son, she moans because i don't visit her when my partner is at work, but she can visit me too, i live round the corner from her, she should be the one wanting to visit her grandson, shouldn't she? She also has not bought a single thing for her grandson, she has lots of money even though she makes out she's poor, she found like £300 randonly in her house one day that had been sitting there for years, and she didn't even spend it on anything so she can't be that poor to be able to save it and not buy her grandson a single thing!!! She keeps saying she'll open a savings account for him and me and my family can add money to it but only she can withdraw money and see the balance😒 why would she be withdrawing money if it's savings for my son?? i think she is being very dodgy, i mean why would i do that, so you can take the money out without us knowing???? Big rant i know but surely i'm not overreacting😡