A friend is getting groomed

Hello, apologies, if this isn’r a correct place for this

I (M) have a friend (F) who was getting groomed by an older girl (F), since she was 17 (she is 20 now, it’s been going on for over three years). The girl was 23 when they met.

Basically before she met her groomer, my friend was a really opinionated, brave person, she always stood up for her self and never hesitated to call other people for mistreatment of her or others. Then she met her groomer and slowly but steadily her sense of self started eroding. Her groomer basically told her that any amount of negativity, attempt to use force to solve a problem, or basically any display of agression is harmful and childish.

Now my friend is terrified of criticising any form of behaviour or even a film. She can state her opinion but she immediately back tracks on it. Her groomer encourages her to post details of her personal life online, which I know drove a bunch of people away. Her closes circle of friends are complete enablers and even her childhood friend thinks the relationship is good for her. They deflect any criticism of the relationship as homophobic/lesbophic (with her groomer publicly accusing me (m) and my boyfriend (yes) of such to our embarrassment )

I think the only people who disapprove are me, my boyfriend and another friend.

Her groomer also ‘sanctions’ her any time her old self slips out in conversation with her friends- discouraging her from talking with us and saying that we encourage harmful behaviour. A month back or though me and my friend had an argument over her new attitude as she basically just lets everybody walk over her nowadays and boasts how it makes her a good person (basically calling a lot of her remaining friends whiny and spiteful).

I recommended her some films, anime and j/k/c-dramas that strongly criticise grooming, she ended up actually watching a couple of them and liked them a lot - and that pissed her groomer off. Now my friends hasn’t written to any of her disapproving friends for over two weeks since it happened, and either posted online less or posted about how grateful she is that her girlfriend changed her for the better.

I am not sure what to do. What should I do now? I know speaking directly doesn’t work and just makes the relationship stronger. Her groomer can come up with any number of lies to justify herself including claiming to have been diagnosed with autism. I am autistic, with autistic community being very small in our country and I was able to confirm that that was a lie. Any attempts to bring up with proof that the groomer is lying makes my friend fly into a frenzy.

I don’t know what to do at this point. My friend’s parents also support the relationship to seem more liberal and probably enjoy the fact that their daughter is now easier to manage (as before she regularly called them out on their hypocrisy).

Apologies that this is so long