Margaret Jane is named executrix in the 1868 last will and testament of her sister-in-law, Margaret (Van Antwerp) Vallance, wife of William Henry Vallance.
There is a death record for a Margaret Vallance from 1915 and a corresponding findagrave memorial, but the 1871 England census shows there was at least one other Margaret Vallance active in Liverpool at the same time so there is no way to tell if the one who died in 1915 is the daughter of William and Margaret.