There are several possible William entries.

1851, Rushen, district 1, schedule 13, Cronkedooney
Esterh Corrin, head, widow, 63, farmer of 11 acres, Rushen
William, son, unmarried, 35, farmer's son, Rushen
Jane, daughter, unmarreid, 28, farmer's daughter, Rushen
Esther, daughter, unmarried, 27, farmer's daughter, Rushen
William, grandson, 10, scholar, Arbory