Another outside possibility (but again earlier birth year than OP has suggested), was a Thomas Henry Kidd born to a William Kidd and Charlotte Hamilton at Grogey townland in 1910. Not known if this Thomas also had a sister Harriet, but certainly his mum seems to have been of an age to have possibly had other children after 1911 census.
Charlotte (Hamilton) Kidd had at least 2 children after 1911- see reply #6