She is behaving like a child, and yet she is an adult.
She can throw a strop, have a tantrum all she likes, you need to find that place in yourself where YOUR well being is more important than her tantrum.
You said you were ND, it seems to me that she is too. She is not getting any social cues at all from you. It is time to sit her down and have an adult conversation. No hints or suggestions, be BLUNT. Darling, no, you cannot stay for 10 days.
I would use phrases like
Darling, we love you, and you know that we love celebrating Christmas with you. But you are an adult now, and you have your own home.
This house is not your main home any more and it is not your partners home.
This is our home, and we are getting older and now that you and ds have left home dad and I would like you to start respecting it as our home.
But before you do that, I would start with the contributions.
I said in a post further up, that my mum changed christmas when I was a similar age, she took the bull by the horns and said to people - what are you bringing? But she give them options like - 6 bottles of wine or 3 desserts? So that each person pulled their weight.
Add in the - so we are sharing the cooking, I will do Christmas day and boxing day, ds you do christmas eve and dd you are cooking on 27th.
I think you will find that if you insist on sharing costs, bringing their share of food, and helping with cooking and chores, that the issue of staying 10 days will disappear.