Feeling Concerned After a Conversation with an Ex-Muslim Friend

Hey, so I know this girl at school I'd consider a friend, but I recently learned she's now an atheist after leaving Islam. I always thought she was just a less practicing Muslim, and honestly, I respect people with different beliefs-many of my friends have various faiths, and we all respect each other. Today, though, when she shared she was ex-Muslim, I gently suggested she might want to revisit the Quran and learn more about Islam, just out of concern. She replied that she knows Islam better than I do and claimed if I understood it like she does, I wouldn't want to be Muslim either. I tried to discuss it, but as someone with strong faith, I felt pretty surprised and a bit offended. She even argued that parts of the Quran were incorrect, which led me to just walk away. I'm not sure what to do now-I might avoid her since we're not super close, but with our small school, that's tough. I'm planning to make dua for her, hoping Allah guides her back. I'm also worried she's been influenced wrongly because she mentioned being extremist before losing faith, but I don't really want to talk to her again since she seems closed to persuasion. If any of you have faced something similar, how did you handle it?