She was unable to compete due to injury in 1998 and became a French citizen in 1999. She defeated Denise Lewis in the heptathlon at the 1999 World Championships. She recorded the best score of the year in 2000 but was forced to withdraw from the 2000 Olympic Games in Sydney due to injury. Barber won the long jump at the 2003 World Championships in Paris but narrowly lost out to Carolina Kluft in heptathlon. Eunice again finished 2nd to Kluft at the 2005 World Championships in Helsinki. Barber was forced to withdraw from the 2006 European Championships in Athletics in Gothenburg, again due to injury. In 2006 she was involved in an altercation in which she claimed she was handled aggressively by police officers during a stop for a minor traffic offense. In 2008 she was sentenced to two months in prison.