Hello KitKat: I see this is your first post here on PC. Welcome to Psych Central. One forum, here on PC, that may be of interest to you would be the Partners of People & Caregivers forum. Here's a link:

https://psychcentralforums.com/partn...ivers-support/

I'm not a mental health professional. So I can't offer you anything definitive with regard to what's going on with your friend. Given what she's been through, she really ought to be seeing a trauma therapist I would think.

You asked how you talk to her about what she experienced. My personal opinion is you don't. She needs professional help. My thought would be to simply let her know you're available to talk (which means primarily listen), or in other ways provide support, to whatever extent you feel you can. Then let her take it from there.

Here are links to 7 articles, from Psych Central's archives, that (hopefully) may be of some help to you in understanding what may be going on here:

What is Trauma Bonding?

How to Recognize the Signs of Trauma Bonding

Healing from a Trauma Bond

The Clinician's Guide to Helping Client's Heal from Trauma Bonds: Breaking Free from Toxic Relationships

https://blogs.psychcentral.com/imper...ship-patterns/

https://psychcentral.com/blog/repeti...peat-the-past/

https://pro.psychcentral.com/exhaust...-being-abused/

I hope you find PC to be of benefit.

P.S. One thing you might do is to provide your friend with a link to the National Sexual Assault Telephone Hotline:

https://www.rainn.org/about-national...ephone-hotline

1 (800) 656-4673 (HOPE)