I know this isn't what you're asking, but what if you just accepted her as is.
That is a gift you can give her.
It doesn't sound as if she wants to change, so let her have her experience of life her way, and, if you have it in you, celebrate her life with her. Allow her to be her with no judgment from you.

She probably has very little interaction with friends/family that isn't somehow filled with judgment that her choices are wrong or that she needs to be fixed.

You may even find some of her beliefs interesting. That doesn't mean you have to take those beliefs on, but you can have discussions about them.
And I am by no means saying let her talk "at" you. Discussions go both ways. You still want her to talk "with" you, and not "at" you.