 Colthorpe akaenda nechikwata chenyika cheU-19 kuThailand kunotora chikamu mu2004 FIFA U-19 Womens World Championships. Colthorpe akazoita kutanga kwake kuzere kweMatilda munaNovember 2005 muGosford, New South Wales apo Australia yakakunda China 31 mumutambo wehushamwari. Colthorpe aive chikamu chechikwata cheMatilda chakasvika kumaquarter-fainari emukadzi we2007 mukombe wepasi rose. Mumakwikwi ekupedzisira ekupedzisira neBrazil, akawana musoro kuti awane zvibodzwa pa 22 Brazil isati yakunda 32. Muna 2010, Colthorpe akabatsira Australia kuhwina sirivha yavo yekutanga muAsia Cup, achinyanya kutamba kunze kworudyi rworuboshwe nokuda kwechikamu chikuru chemushandirapamwe. 