a member

For some context my friend and I are minors and she is mentally underdeveloped and I feel like it plays it this horrific situation. My friend was dating this guy a year or two ago, she was 15 he was 18, definitely illegal but I didn't say anything. They broke up so I didn't think much of it, but I few days ago she told me that he asked to hangout, at the time of writing this she's 16 and he's 19. Anyway she agreed to hangout, he picks her up, drives her to his place, and they chill for a little as "friends". But then one thing leads to another as what she described as "he just kinda did it", I asked her did she consent verbally or nonverbally and she "well no, he just kinda did it". I told her that he raped her and she needs to do something about it, but she's afraid to take legal action and still wants to be friends with him, I tried to call the rape help line for advice but they basically told me it was non of my business and no one would believe me so now I'm here. Not only this but she also told me that a little while after they broke up (before he was 19) he did something similar, he invited her to hang, and she said that "I didn't really consent that time either". I don't know what to do, I want to help my friend but I'm so lost and literally anything would help this situation, I'm not trying to force her to take legal action or anything but I've definitely recommended it a lot. I would like to take legal action on her behalf but the rape hotline told that it wouldn't ever hold up in the court of law because she could deny, so I'm just so beyond lost. We're hanging out again tomorrow so hopefully I'll have a better update on this whole thing soon.Thank you for your time, anything helps.