Chapple-Hyam had studied stud management at the National Stud in Newmarket as a teenager and worked for trainers Michael Dickinson and Barry Hills – employed by her late step-father, Robert Sangster – at Manton, Wiltshire, as well as alongside her former husband. Nevertheless, she effectively started again, from scratch, when she took out a training licence in her own right in 2005.
Chapple-Hyam saddled her first winner, Chief Commander, at Wolverhampton in January, 2006. The following August she made history by saddling the longest-priced winner in the history on the Ebor at York, Mudawin, at 100/1. His £124,640 winning prize money remains her biggest payday to date. She won her first Pattern race, the Group 3 Horris Hill Stakes at Newbury in 2010 and, in 2012, 2013 and 2014, recorded three more Group 3 wins, courtesy of Mull of Killough. Indeed, Mull of Killough contested as series of races in Australia, including the Group 1 Cox Plate at Moonee Valley, in 2013.
Nowadays, Chapple-Hyam operates what has been described as 'boutique' stable of 30 or so horses in Dalham, near Newmarket. Her current stable star in undoubtedly the filly Safforn Beat, who won the Oh So Sharp Stakes at Newmarket in 2020 and subsequently finished second in the 2,000 Guineas at Newmarket.