Purdue returned to competition in June 2010, coming seventh in the 10,000 metres national championship race. That August she improved her 5000 m personal best to 15:23.4 and also bettered her 10,000 m mark with a run of 32:36.75 (a junior record for the United Kingdom). She earned selection for both events at the 2010 Commonwealth Games. After a second-place finish at the Yorkshire Run, she headed to New Delhi where she came fourth in the 10,000 m final and sixth in the 5000 m. She won the junior race at the European Cross Trials in Liverpool in November and went on to take the individual and team titles in the junior race at the 2010 European Cross Country Championships. In her last year as a junior runner, she easily won the competition with seventeen seconds to spare over the runner-up.