Hi Alex,
According to a tree on Ancestry, the death date was 1 July 1951, aged 88 years. no location mentioned, no remarriage mentioned, just shown as Mary. Birth 1863 Wiltshire, England. Joseph is shown as dying on 14 Sep 1911 . Marriage 6 April 1880 - which you stated above.
Looks like there is another researcher interested as they have the paternity case in it, unfortunately it is a Private tree.
Was one of the sons named after the father?
Cheers
KHP