Sancha married the widowed Robert of Naples in July 1304, the eldest surviving son of Charles II of Naples. Charles II died on 5 May 1309 and Robert succeeded him. Sancha was queen for the rest of his reign but remained childless. On numerous occasions, Sancha petitioned the pope for the dissolution of her marriage, as she desired to become a nun. Robert died on 20 January 1343 and was succeeded by his granddaughter, Joan I. Sancha supported her step-granddaughter in the first year of her reign against other factions. She retired to a local monastery on 20 January 1344 and died as a nun the following year.