Maud (otherwise Matilda) was born in Dublin, Ireland in 1230, the youngest child of Gilbert de Lacy of Ewyas Lacy and Isabel Bigod, daughter of Hugh Bigod the Earl of Norfolk and his wife Matilda (Maud), daughter of William Marshall the Earl of Pembroke.
Less than four years later on 12 April 1234, her mother married again; he was John FitzGeoffrey, Lord of Shere in Surrey, England, and Justiciar of Ireland.
When their grandfather Walter de Lacy died shortly afterwards on 24 February, Maud and her sister, Margery inherited his vast estates and lordships in Ireland, Herefordshire, and the Welsh Marches.
Maud and Margery both received a moiety of Ewyas Lacy in Herefordshire, and a share of the lordship with the taxes and revenues that attached to it.
[3] The king granted Geoffrey and Maud, and their heirs rights in the land of Meath held by her grandfather, Walter de Lacy by charter dated 8 August 1252.
[5] Geoffrey was appointed Justiciar of Ireland by his friend and patron, the new king, Edward I in September 1273, a post he held until June 1276; however, he had little success against the Irish of Leinster.
Maud was described as independent-minded, and she usually accompanied her husband on his numerous travels abroad, which included Rome where he was sent on a mission to Pope Nicholas IV in 1290.
Maud was highly protective of her properties, and always ready to enter into litigation at the slightest threat to her lands or privileges whether posed by family members, the Church, or the Dublin administration.