<human>: I was talking to two of my friends at school yesterday - we'll call them Mary and Emma. Emma is a good friend of mine and one of Mary's best friends. Mary and I aren't particularly close, but we still talk quite a bit. She doesn't really take anything that seriously; she's always making a joke.

It was a fairly normal conversation, and nothing seemed off about it. Then at one point, I noticed that Mary had a few scars across her wrist. I didn't realise what they probably were at first, and asked her what happened. They both went quiet. Mary turned her arm away. A few moments later they got up and left to go talk in private. By this point I'd realised what I said. I sat there for a few moments, feeling worried and guilty, then got up to leave (it was pretty much the end of the day and I didn't have any classes left).

I ran into Emma on the way home. I asked her if Mary was alright, and she said "She's really fucked. Nah, don't worry about it, she'll be fine." The first bit seemed kind of sarcastic, but I can't tell if it really was sarcasm or if she was just playing it off as a joke. I can't remember the rest of the conversation, so I don't really know what else was said.

The whole thing just seems so surreal, like a bad dream. Emma told me that I should try and forget about it, but I just can't stop thinking about it. I feel like I should do something, but like I said we're not particularly close and I don't think Mary would be comfortable talking openly about it with me. I want to be able to help, and I don't want her to feel uncomfortable around me because of this. I just feel so helpless.

Summarize the given text in a few sentences.
<bot>: Saw a friend had self-harm scars and want to know what I can do to help, or at least make her feel more comfortable.