Long story short, this is about jealousy. She has put herself into competition with you. You make her feel a level of inadequacy. So she’s trying to return the favor.

A woman did this to me once. She tried to get in between my husband and I. It escalated until we had a massive breakup and she threatened to burn my house down. When I came home from vacation, there was a blow torch in my garage, like warning. This is the short version. She really tried to ruin my life.

My advice is to back away slowly. Don’t be the mirror that she projects her insecurities off of. It’s very dangerous and there are a lot of nice women out there to be friend with.