Mary Kathleen McLeod's birth rego states that her parents, Clara Armstrong and Duncan McLeod were married in Port Huron Michigan 27 Aug 1911.
Duncan is a blacksmith.
From Ancestry.ca I found these births with mother Clara Armstrong in the Bruce and Huron areas.
Mary Mirian McIlwain, b 22 June 1910, d/o Samuel McIlwain & Clara Armstrong, parents married 12 Jul 1906 at Arthur.
Also says she was married before to a Charles Letson.
James Alfred McIlwain, b 5 Nov 1911, no father given, mother Clara Armstrong,
Sam McIlwain died 30 Jan 1909.
Clara's previous marriages: H Hyslop and Sam McIlwain [married Seaforth 1900. Don't know which one the 1900 refers to]].
Actually Sam died 30 Jan 1910 according to his death rego. Also says he was a widower and I never did find a marriage for he and Clara.
Harvey Edward Sutton, b 9 Aug 1909, parents are not married, maiden name of mother Clara Armstrong.
If not married give full name of mother: Mrs Clara Letson, housekeeper for Sam McIlwain.
And Mary Kathleen's birth rego.
Marriages found on Ancestry.ca
Jas Hyslop, 38, b Scotland, living Goderich, labourer s/o Robt Hyslop & Mary Anderson married Selina C Armstrong, 22, b Dundalk, living Seaforth, d/o John Armstrong & Mary Corin/Cown.
9 Oct 1907 Huron.
1901 census has a Clara Armstrong, b 1881, Seaforth census as domestic in a hotel run by/owned by James Weir.
There are several Sam McIlwain's on 1901 census in Seaforth area.