There are alot of descendants of Mary through her female line and the line of Bouillon that she married into. One way you can trace her descendants is through the word huegenots. The huegenot society supports all descendants and alot of people have forgotten that many people who carry ancestry of huegenots are descendants of Malcolm III through the female line and are descendants of The Carolingian dynasty through the female line of Bouillon and Mary. So basically you have one female line supporting 2 ancestors because their are no heirs in the male line because it died out. The original holder of Duke of Castle Bouillon was held by Godfrey De Bouillon who died after conquering and successfully invading The HolyLand.He left no heirs. He sold all his lands and titles to the Bishops Liege to raise money to fight in the first crusade. He was one of eight chief lay leaders in the founding of Jerusalem.