Not sure which Ralph you are after, the one marrying Mary or the one marrying Elizabeth.
If its the one marrying Mary :
1851 census, Garth House, Mickleton, Yorkshire.
Ralph Foster, 26, Lead Miner, b. Middleton, Durham.
Mary ", wife, 26, b. Romaldkirk, Yorkshire,
Jno Addison, son, 5, b. Middleton, Durham,
Jos Foster, son, 1, b. Mickleton, Yorkshire,
HO107/2387/553/16
There is a Margaret Addison next door, age 60, could be Marys mother.
Ralph Forster married Mary Addison 16 May 1849 Wolsingham.
Alan.