She began her racing career by riding out for local trainer Mark Polglase, then attended the Northern Racing College, before becoming apprenticed to Michael Bell at Newmarket. She rode her first winner on her eighth ride in public on Generate, trained by Polglase, in an apprentices’ handicap at Pontefract on 4 June 2000.
That was her sole success of the season and she failed to win one the following year, but from thereon she progressed rapidly, sharing the Champion Apprentice title in 2005 with Saleem Golam, with 44 winners apiece. She rode her 95th winner in September of that year, thereby riding out her claim.
In 2008 Turner recorded her first Group race victory aboard Lady Deauville in the Group 3 Lando-Trophy at Hanover, in Germany. She ended that year by becoming the first British female jockey to ride 100 winners in a calendar year, achieving the feat at Wolverhampton on 30 December.
However, in March 2009, Turner suffered a head injury in a fall on the Newmarket gallops. Informed that, due to the nature of the injury, she would not be granted a licence for twelve months, her season appeared over before it had begun. The trauma of not being able to race-ride weighed heavily on her but, armed with new medical evidence, she successfully appealed the decision, ending the year with 60 winners to her name.