well ... to me yes family is family and all that but we are all still people with feelings that get hurt, and have our own things we get upset about, and things people do and say & behavior we dont tolerate in others ...
my 1/2 sister crossed a line with me that i do not in any way shape or for condone people doing to others let alone a family member & that ended it for me & ive severed all ties with with her and burnt that bridge to the ground.
i dont owe her any explanation why, dont care to discuss it with her, dont want a better late then never flippant after the fact apology . she did what she did because thats her type of character. & i dont care who a person who doesnt think twice about doing stuff like that is be it a stranger off the street, neighbor, co worker or my own 1/2 sister .. i dont need or want them in my life period. end of story.

we hadnt seen each other since our dad passed in 2008. we live across the county from each other but in 2019 my hubby passed away & several months after he passed i called i told her that in 5 (five months) from then then i was going to be within 10 miles of her house for 5 days ( five full days) taking care of other business & told her id like to see her while id be there. 5 months notice & 5 full days of time to see her & she told me she was going to be too busy then & didnt have time for us to get together. 5 months notice id be there & 5 full days for us to get together in & she wasnt able to so much as squeeze meeting the 1/2 sis she hasnt seen in 11 years whos husband of 40 years just died in to meet someplace & drink a cup of coffee with, sorry i got a whole lot more other things to do then to ever again waste my time trying to attempt to darken her doorstep again..
so thats my 2 cents say about it for whatever it might be of help to in you & your sisters situation.