This was a little hard to trace, but I may/may not have something for you to follow:
Have a look at this; it is a marriage, but the name of the person he married is uncertain and given are four possible names: Only one is a Catherine and maiden name is Hewit (note only one T).
England & Wales marriages 1837-2008
First Name Catharine
Last Name Hewit
Image Quarter 3
District East London
Line Number 61
Category Births, Marriages & Deaths
Record set England & Wales Marriages 1837-2005
Collections from Great Britain, England
You may wish to send for the Marriage Certificate. It really is the only way to confirm or exclude the person.
I can understand you not wishing to bombard helpers with information, but did they have a son born in India named Edward?
Keeping to specifics is a good way to go - helpers can then ask questions and if sensible will not bombard you back!!