Brianna was born in Santa Ana, California and attended La Mirada High School.  Upon graduation in 1998, she moved out to Arizona where she became part of the Arizona Wildcat women’s track and field team.  In her junior year she became the first women to win both the long jump and a sprinting event (200m) at the NCAA Championships.  She was also named Pac-10 Athlete of the year in both 2000 and 2001.  Her best year came in 2002 when she competed at the US Outdoor Championships against the best American athletes of the time and went on to earn a gold medal in the long jump.

In recent years Brianna has been competing against a number of great elite athletes.  In August 2006, in cold and wet conditions, she went up against a list of past champions in Great Britain.  11.34s later she crossed the finish line ahead of World Champion Lauryn Williams and Britain's top sprinter Joice Maduaka.