Thanks to Terry Kirkman (a descendant of Mary E KELLY; she was his great grandmother) I now know and have found out a lot more information.
Mary E Powditch was one of the 10 children of Samuel and Amelia (nee Hall) POWDITCH from Wells-next-the-Sea, Norfolk, and she had gone out to INDIA sometime before 1860. Following her marriage to William KELLY on 11 February 1860, the couple had 5 sons.
Circa 1874, Mary, together with her children, sailed for England, the boys to go to a Boarding School at Kings Lynn.
Regrettably, on the way from India, Mary died on board ship (name of ship and date of her death not currently known), although 4 of the boys were recorded on the 1881 Census to be at the Boarding School at 6 Tower Street, Kings Lynn (also at the school was one of their cousins, Herbery Harris)