[2] She attended the University of Technology in Jamaica and began focusing on her running under the tutelage of Stephen Francis as part of his Maximising Velocity and Power Track Club.

[3] However, she suffered a hip injury and only trained sporadically in the rest of the year, missing out on the Jamaican Olympic team for the 2008 Beijing Games as a result.

[8] Spencer ended her season by winning the silver medal at the 2009 IAAF World Athletics Final, running 53.99 seconds to finish behind Walker.

She began making an impact on the Diamond League, finishing as runner-up behind Lashinda Demus at the Prefontaine Classic and the Golden Gala, recording a personal best 53.48 s. She had her first win on the major circuit at the British Grand Prix.

As a result, Spencer was heavy favourite to win the gold medal at 2011 World Championships in Athletics in Daegu, South Korea, where she finished fourth.