Four sons and two daughters from this marriage (Williamson, David. Debrett's kings and queens of Europe. Topsfield, Mass. : Salem House Publishers, c1988, pg. 66). Constance was Robert's second wife (Browning, Robert H. Americans of royal descent. 7th ed., Baltimore : Genealogical Pub. Co., 1986, pg. 321).
Debrett's Kings and queens of Europe has her as a daughter of William II, Count of Provence (pg. 66) as does "Europaische Stammtafeln. Stammtafelf zur Geschichte de Europaischen Staaten" by von Frank Baron Freytag von Loringhoven. 1964. Browning, pg. 503 and WWW site Directory of royal genealogy have her father as William III, Count of Toulouse. Browning, pg. 53 has her as a daughter of William of Provence.