Best Friend Seems Jealous

I honestly don’t know what to do. My best friend and I had a falling out because she was jealous of my relationship with my boyfriend. She went to extreme measures and even messaged his ex because I had ended the friendship. We’ve been best friends for almost 6 years at this point in time and she’s never done anything like this before. I gave it like a month but then I began missing her as a best friend. I reached out to her and she admitted to what she did and how it was wrong and apologized. I’m still being cautious when it comes to her, but I feel like her jealousy is still there. My boyfriend and I have a healthy relationship but she’s that girl that goes from guy to guy and can’t find a healthy relationship. She either chooses guys that are emotionally abusive, influence her in the wrong ways (she got arrested with one of the guys), guys who use her and etc. I don’t know if she’s jealous of my relationship with him, how much time I spend with him, or if she had developed feelings for my boyfriend and was jealous (Her behavior before I stopped talking to her indicated that she may have developed feelings for him). I honestly don’t know if I should remain friends with her because this jealousy still seems to be there, and our relationship can never go back to what it was because my boyfriend hates her now because of what she did to me and he’s the one that I see myself eventually marrying. She also broke my trust by going behind my back so regardless of who I eventually start a family with, I wouldn’t be able to trust her with my kids or whoever I end up marrying. I don’t know if it’s worth repairing a 6 year friendship or just letting it go, but 6 years is a long time to be someone’s best friend. (I’m posting this in teen relationships but I’m technically a young adult)