And for those who say "just ignore her, don't give her the power, just go see your parents anyway"? I did that and my sister came into that nursing home and seeing me got so angry and her behavior escalated scaring my mother and she literally chased after me and pushed open a side door and yelled at me to get the hell out and telling me I am NOT ALLOWED. She was the one behaving badly and an employee walked by and looked at me in an angry way saying to take "this" outside when I did nothing. (both my parents passed away this year).
I tend to get responses of "well it would not bother me, I would just, etc." which totally dismisses what I had to REALLY deal with.