My DD ironed her own thigh when she was about 10. She was "just ironing these (very thin) pants, mum" ... while she was wearing them. I could even see the steam holes of the iron imprinted on her thigh. And she didn't tell anyone, until we saw the wound weeping through the pants.
I took her to the medical centre for dressing and re-dressing every morning for about two weeks. Sometimes the wound had to be scraped. She was very brave.
Then we used a special cream they prescribed after that. And she has no scar at all.
As you say, young skin can heal beautifully with proper treatment.