OK, got them in 1861, James & Mariam, presumably Mary Ann, in Bampton, Oxfordshire - this could be the James Leg & Mary Ann Morse marriage. Children William 6, Sarah A 3, Mary M 1.
I am sure you have got the wrong birth for William - or rather, you need to be certain which family you are following before you go any further. What facts are you CERTAIN relate to the family you are researching?
Jane