Delphine was born in 1284 at the Château de Puimichel in Provence to the noble Provençal Signe family — orphaned in her infancy and raised as the orphan heiress of the Signe family.
At the age of 13 (1297), Delphine was married to Elzear of Sabran (St. Elzear of Sabran, 1285–1323). The marriage remained virginal by mutual agreement — Delphine and Elzear had both undertaken the vow of perpetual virginity before the marriage, establishing the 14th-century Provençal Franciscan-Tertiary virgin-marriage tradition.
Delphine and Elzear lived their virgin-marriage for 26 years (1297–1323) — Delphine undertaking the Franciscan Third Order (Tertiary) vows alongside Elzear, maintaining the systematic charity to the poor, the personal poverty despite their noble-baronial status, and the virginal-marital devotional discipline.
After Elzear's death at Paris on September 27, 1323, Delphine survived Elzear by 37 years (1323–1360) — undertaking the continuing widow-Franciscan-Tertiary life. She donated her Signe inheritance to the poor and to the Franciscan foundations, established the Franciscan-affiliated community at Apt, and personally undertook service in the hospitals and at the Apt parish.
Delphine was particularly close to Queen Sancia of Majorca (1285–1345, wife of King Robert the Wise of Naples) — the virginal-marriage Catholic queen who had similar virginal-marital vows with her royal husband — and Delphine spent multiple periods at the Neapolitan royal court in spiritual friendship with Queen Sancia.
She died at Apt on November 26, 1360 at the age of 76. Her tomb alongside her husband Elzear at the Church of Sainte-Croix at Apt survives in continuous Catholic Provençal pilgrim veneration.