From familysearch.org.
Death of Leonard Thomas Ridler gives mother's name as Mary Ann Tyler:

Name: Leonard Thomas Ridler
Event Type: Death
Event Date: 18 Jun 1957
Event Place: Vancouver, British Columbia, Canada
Gender: Male
Age: 79
Marital Status: Single
Birth Date: 17 Aug 1877
Birth Year (Estimated): 1878
Birthplace: , England
Father's Name: Edwin Ridler
Mother's Name: Mary Ann Tyler

Mike