what should i do

There is this girl that I work with who is not only rude to everyone and always has an attitude, but she also flirts with my boyfriend in front of me and behind my back. She is also talking lots of sh!t about me behind my back, she has touched him the way no one should touch him besides me. I’ve tried to reason with her but she doesn’t seem to care and just blows me off and continues to do it to this day, I don’t wanna turn to violence but it’s getting worse she’s even doing it at school now too.