Well, I am coming from a fandom where RPF characters do ... a lot of bad things, which may affect my general level of surprise/shock. But if someone's writing out their rape fantasy, I don't expect established consent, because that can interfere with the fantasy? You know, the fantasy isn't based on a carefully negotiated scene with safe words, even though if someone wanted to act out their rape fantasy, that's the way it would go. On a similar note, on general memes, I see a lot of BDSM types saying that, when they read/write fic, they're not necessarily going for the realistic, negotiated, carefully constructed scene. They want the scenario that would be unacceptable/awful in real life, because the fic is constructing the fantasy, just like the real life scene constructs the fantasy. I'm not an expert on this stuff by any means, but it makes sense to me that, when people write out their kink fantasies, a lot of it won't align with acceptable behavior in real life. The author definitely should've used a content warning, but I don't think the fic necessarily needed to include established safe words, etc.

That said, her response is upsetting. It is concerning that you have young girls/women who don't understand consent and who confuse the fantasy with how things should operate in real life. It's also ridiculous to expect people to know your non-con scene was all consensual in your head or to say that your non-con scene wasn't non-con; for that, you definitely need some kind of context/set-up. But I'm guessing that you're smacking up against some language/culture differences. I don't think you can change the whole fandom, but hopefully these kids will grow up and get exposed to new ideas and learn to think differently about things, like a lot of us do. And maybe some feminist meta wouldn't hurt. :P