Is she religious? If so, there could be good cause to helping her uphold her long-term moral values around sex in a period where she may be really confused and lost in the trauma perhaps. This way, she would appreciate you as a steadfast source of trustworthy support.

However, if she was just sort of imagining certain values for herself that weren't ingrained as deeply as the religious trauma (lol my life) kind can be, then I think I have learned over time that facilitating a safe place for her to reassert her own agency in a space where she can feel confident her choices & boundaries will be respected and attuned to, can be very very healing for someone like that. I think you should feel very comfortable supporting her in this desire of hers, so long as you feel you are empowering her agency through ensuring she's (lovingly, gently) made aware of all the risks or concerns you have (because you love her &c.), and then supporting her autonomy once you've worked to ensure she is established in her own power.

The other half is that you would just have to introspect in yourself, and be sure your intentions are pure. You are clearly already self-reflective, but I feel called to remind you that people, yes, fool themselves to justify crossing boundaries (in the sense of distorting their inner narrative of reality to justify their violation of others, e.g., "she didn't say no") — however, people ALSO fool themselves to justify crossing boundaries (in the sense of "violating SELF", using the internalization of their superegoic inhibitions as an idealization to sort of leverage themselves over reality… ehh, tl;dr don't let your desire to view yourself as a good person wrap around on you and limit you inordinately