I have a sister 8 and a half years younger than me. We never "got on" because of the age difference, and I was expected to look after her a lot when I was in my teens,and it caused a lot of resentment (on my part), but,hey! she was my little sister.
When she was in her teens she caused a lot of family angst. In the end, we all found it easier to cut her out of our lives as far as we could.
My parents found it all very upsetting, but she causes havoc whenever she touches your life.
I don't hate her,or wish her ill, but I can't love her either.
I live 250 miles away from her,now.
Sometimes I feel I want to try to get in touch,(guilt) but I know the moment I do my life will be in chaos again, and I don't want or need that. Plus ,my DH absolutely refuses to have anything to do with her.
I have her on FB ,so she is able to keep abreast of things happening in my family, but I've set it so she cannot comment on anything, or try to chat. She occasionally sends me a private message, but I've learned to ignore them,especially when she uses emotive ,manipulative language.
She thinks all the "history" can be brushed away,and that because we are sisters it shouldn't matter.
After our Mum died,3 years ago,she wrote some awful things to me which I can't forgive.
I wish I did have a sister that I could have a proper relationship with.
I "make do" with my sister-in-law's (husband's side) and my cousin,whom I am fond of ,but we all live big distances from each other,so it is not easy.