I am going to throw this one into the mix, and perhaps someone else can disprove it.
On the 1861 census at 15 Terrace, Milton, Kent (RG09/470/45/29)
Catherine Martin age 26 married - customs house officer's wife (this has been scored through and Captain's wife entered) born Scotland
Henry A Martin age 8 months - customs house officer's son (again scored through and Captain's son entered).
The head of the household is William Martin (32) a waterman with his wife and children.
Forward to 1871 - Bentley Sreet, Milton, Gravesend, Kent (RG10/890/22/36)
H Thos Martin age 38 waterman born Gravesend (Anc. has Jo Thos)
Catherine Martin age 36 Scotland
Jessie age 7 Gravesend
H Charles age 4 Gravesend
1881 53 Edwin Street, Milton, Gravesend, Kent RG11/872/17/28)
Henry T Martin age 45 waterman born Gravesend
Catherine age 46 Scotland
Jessie age 17 dressmaker Gravesend
Henry c age 14 scholar Gravesend
There is a death reg. for Catherine Martin age 47
March qtr 1882 Gravesend 2a 294
(Henry Thos. can be followed through living with daughter Jessie in Greenwich)
This seems, to me, a likely candidate for Catherine Connor but I cannot find the marriage of Henry Thomas Martin to a Catherine to prove or disprove it - can anyone else?