MIL and I have a history of not really getting on. I find her very critical (everything I do is wrong from want I feed them to the fact I work). I've two boys , 5 and 1.
Mil announced 'I am coming to X's sports day and I will come up the night before and stay'. She didn't ask if it's convenient.
I just don't want her here. I want to spend sports day with the other parents having a nice time and watching my son, not constantly babysitting her. I wouldn't mind but on a previous occasion she had a go at me for ignoring her and not introducing her to my friend in the playground - even tho she had been to the house of my friend in question and met her so many times before, I didn't think I had to introduce her. I just know I will spend the day worrying about offending her by mistake.
How do I phrase it nicely/ make up an excuse or should I just suck it up? As a mum of boys I think maybe I am being mean and when my boys are older I will want to go to my grandchildren's sports day...