Matthew qualified for the LPGA Tour by tying for fifth at the 1994 LPGA Final Qualifying Tournament to earn exempt status for the 1995 season. She soon established herself on the Tour, and her best seasons were 2001 and 2005, when she finished tenth on the money list. Matthew also qualified for the Ladies European Tour in 1995 and plays several events on that tour each season. She won her maiden professional tournament at the Australian Ladies Open in 1996. She won the 1998 McDonald's WPGA Championship on the LET tour. She was a member of the 1998 Solheim Cup Team and first reserve for the 2000 matches held in her native Scotland. When Helen Alfredsson hurt her wrist she was called into the team but Alfredsson recovered and Matthew did not play. She was somewhat controversially left out of the 2002 Solheim Cup team but was a captain's pick for the 2003 team, gaining the Cup winning point. She was a captain's pick for the 2005 team as well. She qualified outright for the 2009 Solheim Cup team. She teamed with Janice Moodie to represent Scotland at the 2005 and 2006 Women’s World Cup of Golf.[17] and was a member of the victorious International team captained by Annika Sörenstam in the inaugural Lexus Cup. She won the 2007 Scandinavian TPC hosted by Annika. In January 2009, she won the inaugural HSBC LPGA Brasil Cup 2009, an unofficial LPGA event with a field of 14 LPGA players and a Brazilian national amateur. Matthew was five months pregnant with her second child at the time of the victory. On 2 August 2009 at Royal Lytham & St Annes, Matthew won the Ricoh Women's British Open with a final score of 3-under-par over second place finisher Karrie Webb. It was her first win in a major tournament. The victory came 11 weeks after she gave birth to her second daughter, Sophie. She was the first player from Scotland to win a women's major golf tournament.