She was an amateur National Hunt jockey until forced to retire after suffering a broken neck in 1988. She worked for racehorse trainers Martin Pipe and John Edwards before taking up a licence to train herself in 1995.
Her most successful horse to date has been Mon Mome, winner of the 2009 Grand National. This victory made her only the second female trainer to win the race, after Jenny Pitman. After the race, even Williams was shocked by the outcome, stating "How can you ever expect that? It's unbelievable." She also trained Teeton Mill, winner of the Hennessy Gold Cup and King George VI Chase in 1998.
She trained Something Wells to a win in the Freddie Williams Festival Plate at the 2009 Cheltenham Festival, saddling the first two home, less than two hours after winning with Kayf Aramis in the Pertemps Final at the same meeting.
- ↑ Grand day for bookies as dark horse Mon Mome wins National at Aintree, www.guardian.co.uk, 4 April 2009, accessed 12 April 2009.