family issues

Nawar

so I have this little sister that got married to this horrible man and I found out so many things about him and decided to tell her like a good sister right ? WRONG! i ended up getting called all these names and even had my own neice against me now that mother's day is coming up my dad thought it would be a good idea to bring everyone together but she doesn't want me there even though I live with my dad and it's my parrty what should I do???