Agnes married in 1221 to Theobald. For Theobald, this was his second marriage, after he divorced his first wife Gertrude of Dagsburg the same year. Theobald was in need of children, since Gertrude was unable to provide him with any. Agnes and Theobald had issue - at least one daughter, Blanche. and one son, Enrique I de Navarra (Henry I of Navarre) who died July 22, 1274.
Agnes died 1231. If she had lived for another three years, Agnes would have become Queen of Navarre.