I've found some more notes from the 1851 census:
District 3, entry 45, pp 18/19
Magher Kew, Maughold:
William CORKILL [as given before]
Isabella wife [as before]
Margaret dau unm aged 18, employed at home
Ellinor dau unm aged 16, employed at home
Margaret dau unm aged 14, employed at home, [two Margarets or a transcribing error??]
John son, aged 12, scholar
Thomas Cottier [as before].
3 servants.

Sue