I think my sister went LC
I think my oldest sister has gone LC with my parents. She hasn't said it explicitly, but whenever my parents try to make plans with her, she always has something going on to explain why she can't see them. Granted, every time it's a convenient and seemingly genuine reason, but after a while the pattern is becoming clear. She visits them maybe once or twice a year for a family holiday/trip.
My parents live much further from me than her, but see me significantly more, and I visit them. I find myself annoyed by my mom sometimes, but she is well meaning. My sister and her both have similar anxiety issues though, and I think my mom's anxieties make hers worse. Ironically, though I think she is my parent's favorite.
I can tell it's a touchy subject, so I am hesitant to bring it up. I don't feel it's my place, but I'm constantly being loaded with the emotional toll of this from my mom.
I'm looking for advice on how to navigate this.
Edit:
My father and I had a really tough relationship growing up. There is obvious unfair treatment in the way I was treated compared to my other 2 siblings, and we mention it. He also takes his anger out on me still (only verbally). However, my sister and he have a good relationship, and she allows him to visit her when he passes through town without my mom. I considered going low contact with him, but I care for my mother enough to bear it and with therapy have learned to largely just ignore him except for under controlled circumstances.