Her earliest swimming achievement was on 16 May 1908. She finished third place at the annual CNP swimming festival. On 9 August she finished third in the 60 metre event at the "Fête de la Villette" and she finished again third in the 100 metre race at the "Joinville-le-Pont" meeting. In August, the sixth edition of the FSAPF world championships, organized by "L'Auto" was held in Bois de Boulogne. On the second day, the Prix Femina was held over 100 meters in the waters of the Seine. Delavelle finished in this race third behind Jeanne Decorne and Eugenia Decorne.