Question Author
Thanks everyone.
I don't get on with my sister, she's a very selfish, bitter person and has relationship issues with my mother.
My partner was going to collect her on Christmas Eve, she is quite frail and infirm and needs lots of care, including washing, dressing and helping to the toilet. She currently has carers 3 times per day. We don't have a downstairs toilet and she can be incontinent. This is why she felt it would be hard work for me. Also with all the cooking etc.
We can't go to hers as she doesn't really have the facilities, she lives in a very small one bedroom bungalow. I did suggest us going to her town and booking a Christmas lunch somewhere locally, but my partner insists that I start thinking about myself and current situation. I'd rather have nothing to do with Christmas, if I had my way.