Checked the census fror Denny on FreeCEN and came up with the following:
1841 - at Haggs, Denny, William Marshall, 29, coal miner, wife Jean, 29, also Elisabeth Marshall, 8.
1851 - at Haggs, Denny, William Marshall, 39, collier, wife Jean, 39, children, Mary,7, and Robert,8. All born in Denny.
Family Search shows the marriage mentioned in the earlier post and the birth (8-10-1845) and baptism (8-2-1846) of Robert and the baptism of a daughter, Jean, 19-3-1848.
Graham.