I think you are putting yourself in a situation with someone who has hurt you a lot over the years. It does not sound like you two are a good match for friends.

You said you feel guilty cutting her out because your parents are friends. Work on this issue with your therapist. You shouldn't feel guilty. Though I understand why you would especially if you are drawn to certain patterns in relationships and have low self esteem.

You're allowed to distance yourself from this person.