Sorry for the confusion with ages....i took the apx ages from the 1851 census (and left out an important comma). The point was that they were not babies but nor adults either.
Thanks for the advice re the numbers of sponsors needed.
On the eve of a departure to England perhaps the family is catching up on baptisms and somehow William and Mary were not baptised earlier. Ann is baptised as a babe as she had just been born.
They may have been waiting in Londonderry to catch a ship to England, having come from somewhere else in Ireland?
That's the feeling I get, that they were somewhere between early childhood and adults.
Most important duty of a baptism sponsor is to support the parents to raise their child in the faith. A person who became a Catholic in adulthood would have received a course of religious instruction from the priest before baptism. They weren't a blank page like a baby. The adult convert might receive the sacraments of First Holy Communion and Confirmation soon after Baptism, perhaps after more religious instruction.
If Francis & Catherine Emmerson were a typical Catholic couple in Ireland, they would have had their children baptised as babies, soon after birth as someone else explained. Word would be sent to a priest that a baby had been born and he would go to the house to baptise it. Infant mortality was high. Unbaptised babies weren't buried in churchyards.
An article on Ireland Reaching Out website describes baptism traditions pre and post Famine.
