"You are brilliant Kity. I will suggest Crisis at Christmas to her and Samaritans."
Please don't suggest Voluntary work, especially with people so vulnerable, she isn't at all suitable.
I had this with my Mother and we have similar now with my eldest DD, except my DD wants to cook dinner.
My Mother came on Christmas day, but she was only a 45 minute taxi ride away. I started to challenge her as soon as the negativity started, she stayed until boxing day. Since she's died, the difference is amazing, even the run up, were she constantly declared it "a lot of fuss about nothing" etc, it took the pleasure out of it.
My DD (child-free,but with DP), has been told that we will turn up now more than an hour before. We would like a no hassle, bring a dish buffet Christmas tea, it's her that wants a full dinner, i shop for it, drop it off and usually put her tree up on Christmas eve, but this year I've told her that it will have to be the day before, because i want CE to myself.
Make sure she's knows to keep her snipes to herself or she gets the fuck out of your house.
You've just got to let her tantrum, you are entitled to your own life.
For those saying that "it's only September", you've got to start early with these people, so it somewhat blows over.