Sister (33f) thinks my husband (31m) and I (33f) are ruining her Christmas

My husband doesn't want my twin sister to stay with us over her Christmas vacation. Honestly, I understand. My sister lives in another city 6 hours away, but she likes to come home when she can. I really do like when she can visit- we were each other's best friends since we were little, and I love her more than anything. We always have fun talking about some book or game, we can spend hours just on this.
However, her stays are almost always stressful. As I can't take vacation as long or as often as she can, I of course have to work when she's here. She gets upset when I have to work, or do chores around the house, or even take a nap because I'm exhausted, saying "But we haven't spent that much time together, and I'm going to be leaving in a couple of days." It doesn't matter if we've, in fact, spent the whole day doing things together, she will still say that.
And it doesn't help that she and my husband don't have the best relationship. My husband is kind and thoughtful almost to a fault. He coordinates and arranges events my twin will like even if he won't be participating in them. When he buys me something, he gets something for her, too, so she won't feel left out. Even when we were dating, my husband went out of his way to help her; we drove six hours just to help her move across town. Three times.
But most of the things that have strained their relationship the most were things that my sister had done to me. When I moved in with my husband, she burst into tears when I was having her stay at my house, saying that our mom and day were barely functioning after I left and they said I "ruined the family". When I got married, I asked her to be my Maid of Honor, but she refused to come to the rehearsal dinner because it was on our birthday (as we?re twins). On the wedding, when the DJ asked if she wanted to say anything (as the Maid of Honor usually gives a speech at the wedding), she said "no, I'm good". Just on Thanksgiving, he overheard her say "I will categorically not **** this up because of you." to me while we were making pies together. It was supposed to be just a fun little activity, but she suddenly started treating it as if it were the most serious thing in the world. We had already had several pies (that she had made, no less) that were perfectly delicious.
These things stress him out even more than they stress me out. I'm just stressed out because I have to do my best to make her happy while also working, cleaning, and making my husband happy. My ADHD makes this very hard for me to juggle everything, though I do my best.
During the summer, she and I discussed her finding a place to rent so she can stay longer during the winter holidays. However, last night she asked if she could stay at my place for 17 days, something my husband and I are not prepared to do. I asked her to stay at a rental this Christmas because of COVID and me struggling to keep everything up. My sister says I can't make my issues with ADHD everyone else's problem. Am I wrong in this? Please help, I don't know what to do. Everyone is so unhappy, and I can't fix it.
tl;dr:
My incredibly intense sister, who I love very much, wants to spend 17 days for the Christmas holidays with me and my husband. My husband finds her just as intense and stressful despite his best efforts. Even though we have discussed her renting a place for the Christmas holidays since summer, she hadn't looked at any rentals when she asked to stay with me last night. She thinks I'm not trying hard enough for her, but my husband and I already do so much. Please help.
ETA: My sister and I are twins. I?ve gone back to use twin in lieu of sister occasionally to help with clarity. Sorry for the confusion!


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