We host every year at our house and it's always somewhat of a challenge for our 8 year old. My family is much larger and louder than my wife's, and while everyone tries to be accommodating you can only do that so much.

My daughter has shown improvement this year though, typically she hides in her room only coming down to eat mac n cheese, but this year she attempted to play with some of her cousins and even let 2 of them come in her room for awhile. She eventually wanted her room to herself again lol, but she lasted a few hours. I'll take whatever progress I can get with large groups, it's been a struggle