Assuming that “genero” in the following document was used in its strict sense of son-in-law, Ribald’s wife was Ivo’s daughter: “Ivo Talliebois” donated property to St Mary, York, for the soul of “uxoris meæ Luciæ”, by undated charter witnessed by “Lucia uxore mea, Ribaldo genero meo, Radulpho Taillebois…”. The difficulty is that “gener” was sometimes used in medieval documents to indicate brother-in-law. Ingulph's Chronicle of the Abbey of Croyland records that the "only daughter" of "Ivo Taillebois…[and] his wife the lady Lucia" married "a husband of noble rank" but "died before her father". It is possible that this passage refers to the wife of Ribald. Assuming that this was the same wife of Ribald, her name is confirmed by the following document: “Ribaldus frater comitis” donated property to St Mary, York, for the soul of “Alani comitis et Beatricis uxoris meæ”, by undated charter... 1
Beatrix married Ribald DE BRETAGNE, son of Cte Eudon I DE PENTHIÈVRE, Duc de Bretagne, and an unknown mistress.
1 Foundations for Medieval Genealogy, Medlands, Beatrix.