I've always had a difficult relationship with my mum and I'm sick of her constant judgement on everyone- not just myself, literally everyone and anyone we know. She's extremely bitchy and makes very cutting comments about people who are virtually strangers to her. I really hate this part of her personality and find it hard not to end up in a disagreement and bite my tongue.
This is the exact reason why I haven't asked her to help watch my DD for a couple of hours because I know as soon as she does she will pick holes in everything and make out to everyone that I'm cheeky and she's my full time nanny! She did this when I got married, told all her friends she was exhausted with wedding planning, she didn't do a sodding thing!!! Other than come to see my dress and turn up on the day!
So I carry on and I keep my distance.
My Dad asked me on my own recently if I would let DM watch my DD for an hour or so so that she can enjoy some time alone, as apparently she stopped work to help me out and I've been unreasonable by not letting her help until now. I NEVER asked her to help with child care and certainly never gave her any indications of the sort.
Fast forward to now and recently I had a hospital appointment and thought it would be a good time to see if mum wanted to watch DD whilst I went. All went well and shockingly no repercussions....my DD loved it.
But now she's funny with me if she offers and it doesn't work out or I'll say no and she won't do anything that day and then blame me for messing up her plans?! I find myself apologising even though I know I made it crystal clear.
I'm struggling with how to handle the situation other than emigrating! 
Any advice would be really appreciated.