Caribbean Junior Championships, where the 16-year-old Russell took the 400 m silver medal win a personal best of 53.68 seconds and helped the Jamaican 4×400 metres relay team to the gold medals. She was selected for the same events at the 2010 World Junior Championships in Athletics. Although she was a little slower in the 400 m individual event, being eliminated in the semi-finals, she won a medal with the Jamaican team, which ran its fastest time of the year (3:32.24 minutes) to claim the bronze medals. She competed internationally in her fourth different event of the season, choosing the long jump for the 2010 Youth Olympics and placing seventh in the competition. The 2011 season saw Russell set personal bests in all the disciplines she competed in, bar the jumps. She focused on the 400 metres hurdles at the start of the year, which culminated in a victory in the under-19 section of the 2011 CARIFTA Games in a personal best of 57.71 seconds. She also won relay gold with the Jamaican team at the competition. In May she ran track bests of 24.10 seconds for the 200 metres and 53.55 seconds for the 400 m. In June she won her first senior title at the Jamaican Athletics Championships, winning the heptathlon with a personal best score of 5361 points, including a javelin throw best of and an 800 metres best of 2:18.47 minutes to finish the competition. The 2011 Pan American Junior Athletics Championships was the biggest international event of her season and she finished with a heptathlon silver medal behind Brazil's Tamara de Souza, setting bests in the shot put and 100 metres hurdles along the way. World Junior champion Russell began to specialise more in the hurdles in 2012. She repeated her hurdles/relay double at the 2012 CARIFTA Games and was also the long jump runner-up. Her season focused on the 2012 World Junior Championships in Athletics. She entered as the world leader in the 400 m hurdles through her new best of 57.04 seconds at the national championships in June. She was dominant at the competition and won the gold medal by a margin of over a second, setting a new best time of 56.62 seconds. This made her the second Jamaican woman to win the title, following in the footsteps of Kaliese Spencer She then anchored the Jamaican 4×400 m relay team to the