I suspect the 1851 census is showing William Stephen and his wife Catherine Cowin who married in 1814. Their daughter Eleanor married Robert Kelly hence the grandson Robert aged 5.

You may be looking for the daughter of William Stephen and Elizabeth Kelly who married in 1797. For the first few years the children seem to be registered only in their fathers name.

There was a death of a Mary Stephen in Apl. 1803 daughter of William Stephen of Ballamoar and a subsequent christening in June 1803 of another Mary.

The Ballaugh burials indicate the mother Elizabeth ( Ballamoar) died 1832 aged 55 and a death of a William in 1841 but you may wish to confirm this through the wills listed on Brian Lawson's site.

Len Faragher