Matilda's parents were Samuel Mullan and Elizabeth Alice Simpson.  His father was a farmer.

Ontario, Canada Births, 1869-1907 Record info about Matilda Mullen
Name: Matilda Mullen Date of Birth: 1 Apr 1883 Gender: Female Birth County: Wellington Father's Name:Samuel Mullen Mother's Name: Elia Jane Mullen Roll Number: MS929_62 #037020

Note on her birth registration the surname is Mullen.

Her date of birth on the 1901 census is listed as Mar. 31, 1883.