The family appears in the 1841 census
Ramsey, district 2, page 5, College Street
Philip Quiggin, 45, shoemaker
Anne, 45
Anne, 15
Jane, 15,
Catharine, 15
Ellinor, 12
William, 10
Robert, 7
Margaret, 2

This makes John the eldest of 8, though I can't find a baptism for Robert.

I can't identify John in the 1841 census.

I can't postively identify any of the family in the 1851 census - ? left the Island.

The date for the John Quiggin/Jane Quayle marriage is correct, but is it the same John ?