I assume you do not have Mary's maiden name.
Images of civil birth records stops in 1920 because of Irish privacy rules.So if Mary and Michael were the only two children, records are not available.
Civil marriage records are available thru 1945 but I looked for a Michael Killeen marriage 1920-1923 in the Gort area and did not see a record.
I believe this 1911 census record is for Michael and his family.
The townland you mention Cahercalla is not the correct spelling possibly is was Cahercarney.
Let me know if you have further info on the family. I'm going to check one other data base.