She was 13 years old when she won gold at the 1994 Winter Olympics. Kim Yun-mi of South Korea earned that medal in Lillehammer, and sources note she was 13 years and 85 days old.

Quick context

  • Athlete: Kim Yun-mi.
  • Event: 1994 Winter Olympics, short track speed skating relay.
  • Age at the time: 13.

Detail| Answer
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Skater| Kim Yun-mi 1
Country| South Korea 1
Gold medal year| 1994 1
Age when she won| 13 years old 18

TL;DR: a South Korean speed skater won gold in 1994 at age 13.