His wife and mother are the same person, Emma Darrell, daughter or sister of Duncan Darrell. I can find as many sources supporting one view as the other.
His Overview states, "The identity of his wife is not known. " and "The identity of his wife has evidently never been found in surviving records, nor is the date of his death known, but he was still living on 23 November 1234."
This states Marmaduke married sister of Duncan Darrell.
https://archive.org/stream/thwinggenealogic00thwi/thwinggenealogic0...
Thwing : a genealogical, biographical and historical account of the family"
8 THE TWENGE FAMILY IN ENGLAND.
[Sir Robert de Twenge, ..]
II. (1240), and with Earl Richard arrived in Palestine, October,
1240. He was succeeded by his son Makmaduke, who espoused
Emma, sister and heiress of Duncan Darrell, and was succeeded
by his son
ROBERT, Lord of Kilton Castle, who married Maud, the
widow of Sir John de Oketon. Children :
A genealogical and heraldic History of the Commoners of Great ..., Volume 2 according to a web site states, " Sir Robert De Thwenge, deputed by the other barons to repair to Rome ... His son and heir, Marmaduke Thwenge, espoused Emma, sister and heiress of Duncan Darrell"
The dormant and extinct baronage of England: or, An historical and ... according to same web site states, "Of this family, anciently lords of Kilton Castle, in Cleveland, the first person noticed is Sir Robert De Thweng, knight, who was succeeded by Marmaduke, his son, who married one of the sisters and coheirs of Duncan Darrell, and had issue"
https://www.wikitree.com/wiki/Thweng-25 cites, " I believe that Emma is Marmaduke's mother, not his wife, per CP:
"This confirms with the pedigree put forward in a case of 1309 relating to Lund, when it was stated that from Emma, one of the 3 sisters of Duncan Darel, her interest in Lund descended to her son Marmaduke, the ancestor of the then Marmaduke de Thweng. [Ref: CP XII/1 p735(f)] "
Robert FitzRobert de Thweng, Lord of Thwing is the profile for the father of Marmaduke. It claims that he was the husband of Emma, not his son.
Who do you think is the husband of Emma?
