I knew a girl that won the UK national 1500m championships in her age group, maybe around 14/15. I have a feeling the time was like 4:37 but it might be nearer to these times, 4:30-4:20, I can't quite remember. Perhaps 4:27. All I remember is that I was doing like 5:30 or something, and 2:27 for 800 (won it in school at 14), and was beat by her in both (she was a year younger too). Very tall and slim girl. But she always wanted to do tennis instead and gave up on running. Tbh, I doubt she ever trained for running, and was just naturally talented, but I have no clue on how far she could have gone. It's good to see these young new runners coming through, Judd, Cain etc.