The primary source which confirms her parentage and marriage has not yet been identified. Borderie suggests that Judicael Comte de Rennes was the grandson of Duke Gurwent, but he does not cite any primary source which supports his reasoning. 1
Marriage Information:
Unnamed daughter of Gurwent de Bretagne, Duke of Brittany, married Bérenger, comte de Rennes. (Bérenger, comte de Rennes died before 931.)
Sources
1 Foundation for Medieval Genealogy, Medlands, daughter.