If self harm was for attention, we’d do it in front of your face.
We wouldn’t barricade our bedroom door. Lock the bathroom door. Cover it with long sleeves. Do it places no one will think of looking. Look so ashamed when you ask to see it. Be so socially aware of ourselves. Be laughing one minute then second the next. Keep everything from you if it was for the “attention”.
It just so happen you found out, probably by accident. Don’t get involved.