Ada Montdidier de Roucy was born circa 1117 in Roucy to Hugues I de Roucy (c1090-1160) and Aveline de Pierrefonds and died after 1172 of unspecified causes. She married Gaucher II de Châtillon-sur-Marne (c1110-1146) .
Children
| Name | Birth | Death | Joined with |
| Guy II de Châtillon-sur-Marne (c1137-c1171) | 1137 Châtillon-sur-Marne | 1171 | Alix de Dreux (1145-1209) |
| Gaucher de Châtillon-sur-Marne (c1140-1188) | 1140 Châtillon-sur-Marne | 1188 | Helwide de Nanteuil-la-Fosse |
Footnotes (including sources)
| ‡ General |