I had a friend with ADHD and I always knew she was a little bit different. I found out when her mother told my mother who told me. Now we talk about it sometimes, but she's usually kind of embarrassed. Also, not all of her friends know so sometimes they make fun of her and I have to tell them off. I got diagnosed a year ago and I'm still not sure I have ADHD but when I told her, I basically sat her down and told her.

It's probably really good you had the conversation with your mom already because it makes the subject less taboo. I would recommend just going for it. You've already paved the way really well. If you keep losing courage right before you mention it, I find it's way easier after I get the first word out. Good luck with everything.