Marriage of Sir Marmaduke de Thwenge to Lucia de Brus

Yorkshire Pedigrees page 372 

 Lucia, daughter and co-inheritor of Peter de Brus II, Lord of Skelton and Helewise, eldest daughter of Peter de Merley, sister and   co-inheritor of her brother Peter de Brus III ; Married 27 September 1237, had Brotton, Danby, and other lands as her share ; died 1272.

On her death of her brother Peter she obtained the patronage of Guisborough Priory jointly with her sister Agnes, Wife of Walter de Fauconberg

Note: I have problems with the date of Lucia's marriage. Her children were born in 1250's which leads us to believe that she was married in the 1250's