Yolanda exists only through tertiary sources at present. If she exists the current dates would places her here as a brother of Erasmus II.
She is identified by three different names in various sources. In the French Wikipedia page on her purported spouse Wédric II “le Barbu” I find this statement...which hardly makes sense!
“ De son mariage avec Rasse de Chièvre il eut un fils : Gui de Chièvres, dont la petite-fille Ève Damison de Chièvres fut la fille de son fils homonyme Guy.
Wédric eut quatre autres enfants : Thierry, Gérard, Meuzon et Ade. Gérard suivit Godefroid de Bouillon à la première Croisade. Ade, épouse de Fastré d'Oisy, fonda un couvent de femmes à l'abbaye St-Martin de Tournai et continua la maison des seigneurs d'Avesnes.
En 1076, il meurt, s'étant repenti, il se fit enterrer dans l'abbaye de Liessies entre l'ancienne et la nouvelle église du cloître.”
“From his marriage with Rasse de Chièvres he had a son: Gui de Chièvres, whose granddaughter Ève Damison de Chièvres was the daughter of his namesake son Guy.
Wédric had four other children: Thierry, Gérard, Meuzon and Ade. Gérard followed Godefroid de Bouillon to the first Crusade. Ade, wife of Fastré d'Oisy, founded a convent of women at the abbey of St-Martin in Tournai and continued the house of the lords of Avesnes.
In 1076, he died, having repented, and was buried in the abbey of Liessies between the old and new cloister churches.“
This Rasse de Chièvre is probably a misname of Rasse de Gavre because the Gavre family was not in possession of the lordship of Chievers until 1138. However I also find an entry for Yolande de Gent b. 1002 in Tournai d. 1049 in Avesnes-sur-Helpe as wife of Wedric II. These could all be the same person. (as previously indicated these are tertiary sources and machine translations)
Finally, Geni misnamed the purported spouse. Wédric II le Barbu, mort en 1076 Said to be husband of Yolanda did not bear the nickname “le sor” that belonged to his father Wédric Ier le Sor ou le Roux (vers l'an mil) est un seigneur de Leuze et de Condé, d'une province du Nord de la France, la Thiérache. Il est le vassal du comte de Hainaut Régnier V qui possède toute la région d'Avesnes (although there are a number of sites that show both it is likely a case of internet copy and paste). Is Wedric II being confounded with Gueric II a sibling who seems to bear the corr3ct nickname?