David is shown in http://www.findagrave.com/cgi-bin/fg.cgi?page=gr&GRi...
Mary and one daughter are also linked
Name: William Richards
Birth Date: 6 Aug 1871
Birth Place: Wales
Death Date: 11 Apr 1934
Death Place: Nesbit, Luzerne, Pennsylvania, USA
Father: John Richards
Mother: Ann Davis
Spouse: Mary Luton http://www.findagrave.com/cgi-bin/fg.cgi?page=gr&GRi...
It may well have been convenient for both of them then - it was very hard to bring up a family so, can't blame her
I think where it said "number of children living" they, themselves as a couple, did not have any so....