 On 12 June 2003, at a European GP meeting in Riga, Latvia, Cuddihy broke the junior Irish national record in the 400 metres with a time of 53.21 seconds.At the NCAA Championships in Sacramento, California in mid-June 2003, Cuddihy came second with a time of 53.85 seconds.The following month, she won a silver medal at the 2003 European Athletics Junior Championships in the 400 metres.