Where are Boundaries for Caregivers?

Here is the situation. My mom and dad have a live-in caregiver. She is great as a caregiver but I think she is pushing the envelope a bit. See, she has given up her house to her daughter and now is staying at my parents' house. So she invited her ENTIRE family over to my parents' house for Xmas dinner. She is going to cook. Now her entire family consists of four daughters, various grandchildren, a son-in-law who is out of work and an ex-husband who, according to her, is an alcoholic. My parents are good people and are very trusting. I have never met her son-in-law or her ex. This is my parents' house and they have never met either man as well. So there will be over 9 people from her family at my parents' house and my parents and me. I just feel really uncomfortable with this situation. I don't know the two men and I don't like them coming into my parents' home like it is nothing. I understand that my parents' caregiver has given up her home to help my parents but their house is not HER home and I feel like she is treating it that way. I feel like she is taking advantage of my parents. My dad is afraid to upset the apple cart because he feels my mom is getting good care. But he never liked crowds, even his own family. I don't want to go there to feel like an outsider in the home I was raised in. I also feel like this woman is taking a position that supersedes the position of my brothers and I. She has family over so often at their house that her family is becoming my parents' new family. When I go, which is as often as I can, all I hear about is her family and her family woes. I'm sorry. I don't care. (Sorry, but I don't. I have enough to deal with, especially since many of these problems are of their own making.) My dad spends so much time listening to her woes but I feel like I dare not tell him anything about what is going on with me. I don't feel he really wants to hear or won't really care. On the phone he goes on and on about this caregiver and when he DOES ask me about what is going on with me I get the message that all he wants to here is "fine." I have offered to go live with my parents but my father refused. So now this woman has taken over and my father, who used to be so strong-willed is letting her take charge of his home. I have heard of so many situations where the caregiver took total control of an older person and even came between the parents and the children. I am just so uncomfortable with all of this. But I cannot talk to my dad because he tells me to butt out. Soooooo. Here I am, back at square one. Wondering what to do.