think the two girls in 1841 must be his sisters
found this on the IGI ext rec
birth/christenings
name; mercy ann watson
christened 19th jan 1821
place; great meeting hors fair-presbyterin,banbury,oxon.
parents james and mary watson.
name;
mary ann watson
birth. 14th oct 1821
chr. 4th dec 1821 at the same place as mercy ann watson.
parents. james and mary watson.
there is also a george watson and a thomas sabin watson both christened there with the same parents
cannot find james christening or birth
but going by this james probably married after 1841 and his wife died before 1851
so will not be able to find anymore out about james and his first wife.
will have a look to see if i can find his parents marriage.