 Following her silver medal at the European Athletics Junior Championships in 2003, Cuddihy moved into senior competition.At the 2003 World Championships in Athletics held in Paris, France, Cuddihy qualified for the final of the 400 metres with a time of 53.68 seconds.She participated in the 2004 Irish National Indoor Championships in Belfast, Northern Ireland, where she won the 400 metres in a new all-comers record of 53.50 seconds over Moushaumi Robinson.