Two questions in one... Should i get help for her? and Should i stop being friends with her?

My best friend and i have been friends for 2 and a half years. when high school came and we had issues around October time. I was mad cause she was dating this guy who would physically abuse me and her and all he used her for was sex. she said i didnt support her in her decisions. we stopped being friends for good. i heard tons of rumors (which ended up being true) of her screwing tons of guys. we started talking just a couple of months ago and we became friends again. i found out she has screwed about 15 different guys. and has thought she was pregnant three times. im worried about her and i dont know if she jas any stds. Also, she has talked major **** about me behind my back and has stole four of my boyfriends. should i stop being friends with her?