She is listed as Mary Henshaw on her son Thomas Edward's marriage certificate.

1911 Census / Ontario / Dufferin / 6 Garafraxa East / page 6
Nodwell Edward M  Head M Mar 1879 32  
Nodwell Margaret F Wife M Mar 1884 27 
Nodwell Thelma F Daughter S Jan 1911 4/12 
Nodwell Harriet J. F Mother W Apr 1839 72 
Nodwell Bella F Sister S Sep 1880 30 

Vital Statistics Index, deaths, 1926, reel 14, Reference number 012172-26.  Copy on file.

A picture of her tomb stone is on file.