Your ex-friend is in a cult, and unfortunately there’s little you can do about it until she runs out of places and ways to hide from the truth. Especially since she’s probably filing a void in her mental space by being on the side of self-righteousness - it can be nice to not have to be so unsure of yourself especially when there’s such a large number of similarly-thinking people to take security in your self-worth with. It’s kind of the basis for cults and mob-mentalities - all your “thinking” is already done for you.

If there’s any chance of you two being friends again, it’ll have to be after she hits the aforementioned brick wall, and she’s finally forced to admit she was wrong. If you want to regain that relationship, the best you can do in the meantime is try not to attack her directly any time you have to interact with her - just lay out the facts about the erroneous beliefs she’s chosen without any embellishments or exaggeration. Show that the only “side” you’re on is the side of truth and facts - even if she doesn’t choose to believe that now, down the road when she’s re-evaluating her choices, that will stand out.

If you can, try to give examples of the injustices turned on their head so that she winds up on the losing side - when your examples are effectively the same with only the roles reversed, it’ll put shreds of doubt in her mind even if she outwardly rejects it. Given enough such doubts over time, it may just help her come around a bit faster.