She began her career in snooker at the age of 14 and won her first Ladies Snooker Championship in England, when she was 15 years old. She moved to US in 1998, winning her first WPBA Classic Tour title in 2000. By the end of 2001, she was ranked as the number 1 player.
By the end of 1998, Karen was ranked #24. At the end of 1999, she soared through the rankings, all the way to #4. By the end of 2000, she was ranked 2nd in the world, though 2002 proved to be her most successful year to date.
Karen became the first person to win all six Classic Tour events in one year. She won the Silver Medal at the 2001 World Games in nine-ball pool and placed 2nd at the WPA Women's World Nine-ball Championship. Before 2001 ended, Karen found herself at the top, the #1 ranked female player in the world, and remained there for 2 years.
For 2007, she was ranked #5 in Pool & Billiard Magazine's "Fans' Top 20 Favorite Players" poll.
