Although there is a historical record giving her name as Matilda (LNU), there is another record recording her name as Maud:
"The History of Parliament: the House of Commons 1386-1421," ed. J S Roskell, L Clark, C Rawcliffe, 1993.
http://www.historyofparliamentonline.org/volume/1386-1421/member/ge...
Some researchers believe that Thomas had a 2nd wife, Isabel Field, but I doubt it as she and her husband both outlived Thomas. Two problems, however -
1 - Some researchers believe Matilda died in the 1390s; If so, who is the mother of Elizabeth (1413)?
2 - Elizabeth (1413), was born 34 years after Thomas & Matilda's 1st son, John (1379). If Matilda
is her mother and we have her birth date correct - abt 1360 - she would have been 53 years of
age -- possible but beyond normal child-bearing years.