what to do about this please?

[.]

my boyfriend's sister has once again started drama she unblocked me on fb I was able to see her name on her moms page when her mom added me then she blocked me again so I search for her come to find out shes talking about me my relationship and her family members and other people that she "hates" I called her out basically on twitter and what does she do deletes all her accounts lol and then goes on to talk more and say on her page that she makes people things for that im bitter and she has to "Deal" with me again when I didn't even do anything to her why is someone's sister crazy like this and plays victim and runs when shes called out seriously now im afraid his mom will think im the bad guy when shes done in this past
shes said sorry before but then turns around and starts this drama again she acts like an ex girlfriend and its very strange that someone will go to such lengths to attack me when she doesn't even know me