Do you think it is acceptable for family not to speak to each other?

My family has endured a ton of deaths and the women are definitely in charge around here. Now, a great niece of mine, won’t speak to her father and most recently, my eldest sister is not speaking to me. She is 65, or something like that. I wrote her a letter about some of her skeletons that turned up. I kept it in a couple of years and she was not approachable, even, beyond reproach. Thanksgiving, she and her husband did not speak to me. I was business as usual, with a load off my heart. I think it is horrible for family not to communicate. I know we can’t choose them. But I believe we should all try to tolerate and communicate. There has been no abuse to my great niece, that is the only reason I will think of for refusing your kin, even though the mental abuse is DEEP in my family. What do you think?