Very little is known about the early life of Roesia de Verdun before her marriage. de Verdun was the daughter of Nicholas de Verdun of Alton, Staffordshire and Clementia, daughter and heir of Philip le Boteler, through whom Clementia brought the estates of Stoke Farthing and Wilsford to the de Verduns. She was also the widow of William Perceval de Somery. The agreement to marry occurred on 4 September 1225. She was the second wife of Theobald le Botiller. As his second wife her five children were not heirs to his lands but they were eligible to be heirs to hers so she and they retained her family name. When her husband died at Poitou in 1230 during the English invasion of France, de Verdun claimed her inheritances and paid the taxes to be allowed remain unmarried. She applied to be a femme sole and retain her independence. The king authorised Maurice FitzGerald to grant to her her lands in April 1233. She built Castleroche, seven miles northwest of Dundalk, in 1236 to defend her lands. She gained a strong and powerful reputation. However she was also very pious. de Verdun founded the Augustinian priory of Grace Dieu Priory in Leicestershire in 1239. As time went on however the pressure to marry again increased until de Verdun decided to become a nun by 1242 she was a member of the community at Grace Dieu. Her son inherited fully in 1247 when she died. Though originally buried at the priory, in the aftermath of the dissolution of the monasteries, the villagers of Belton reburied her in their village.