How to explain self harm scars to kids that are not mine?

With my own kid I plan on telling him that mommy did that when she was very sad and had no one to talk to and that's why it's very important that he tells me about his feelings and that every emotion is ok and that I'm always there for him. So far so good, right? (Seriously though, do. you think that's good?)But what am I supposed to tell other kids? The other day a ~2 year old girl at the lake asked me about it and I didn't know what to do. I don't know if her parents would want me to say what I would say to my son so I ended up saying I fought with a tiger but I won and now it's leaving me alone. It's totally an analogy, but I'm sure she doesn't get that. Now my husband said that she's gonna have tiger nightmares for the next 3 years.So what would have been the right answer? Ask your parents? Long story? You wouldn't understand? The truth?Help. via /r/Parenting http://ift.tt/2sayhPR