What are some ways that you demonstrate to single women how they should expect to be treated?

A friend of mine is in a relationship with a guy who is "the best partner she ever had" (which I can believe, given her history - she's in her 30's and every other partner she's had since she was 15 was abusive in some form or another) but she still puts up with a lot of things that tell me pretty firmly that she doesn't value herself enough. Example: she made reference to "you know, when you have to do some sexual things you really don't want to do", to which I responded "I don't do things I don't want to do. It's non-negotiable, and my partner understands and respects that and doesn't ask for those things". I genuinely think that was a brand-new concept to her - she'd never heard of women who refuse to do things they don't enjoy.

I've also been pretty open about the fact that I'm not only not into BDSM, I don't think it's a particularly healthy lifestyle (particularly 24/7 dom/sub arrangements). She admitted she really wants her boyfriend to "collar" her, since he'll never want to get married again so that's the closest she'll ever get to that kind of relationship. She knows I wouldn't support that (and I honestly kinda doubt he's really into that), though I'm not sure how much it would impact her decision.

She's not really in a position financially to live anywhere but with him, and due to a number of factors she's not going to be able to improve her financial situation for several years (mostly related to a lack of education and inability to access it). I've known her boyfriend awhile, and his ex has nothing negative to say about him other than that "we were too young when we got together and we grew apart", so as far as value goes he's actually pretty high value when compared with her own exes - they just happened to have set a low bar for her by the time she met him.

Is there much else I can do to demonstrate what kind of behavior she should actually expect when it comes to how to value herself? I talk about how my own spouse (definitely a HVM, although I didn't keep strict adherence to FDS rules) treats me, which I honestly think she deserves to have in her life.