On the same them of ages - if I'm reading it right, wouldn't Thomas be a bit young to be married too?

"Thomas Cain, the father of John and Thomas, had married at Lonan, November 16, 1809, Ann Killip, daughter of William Killip and Jane Kewley. Thomas Cain was perhaps the son of James Cain, baptized at Onchan, August 9, 1795, although I haven’t located any proof for this."