Hi Munchies
maybe there was some sort of a trend around this time as I have almost exactly the same situation with my great grandmother!
On the 1871 census she is the wife of George Fisher.
They had 4 children and the birth certificates give her name as Caroline Pitts formerly Fisher. I cannot find a marriage for them.
I had a terrible job finding her in 1881 as she and the 4 children appear under her maiden name Pitts - and she is recorded as a widow and has another child.
By a sheer fluke I discovered that there was another entry for the same house and she was actually living with a Richard Lock. I sent for the birth certificate of the youngest child and discovered he was Richard Pitts, mother Caroline Pitts, formerly Pitts - and the icing on the cake? father Richard Pitts!!
By 1891 she had another child and this time the birth certificate says - William Lock - mother Caroline Lock, late Fisher, formerly Pitts - father Richard Lock.! I cannot find a marriage for Caroline and Richard Lock either.
As far as I can see my great grandfather, George Fisher, is alive and well on the 1881 census, living as a boarder in Hull, and say's he is unmarried....
There is also a very small time slot between the birth of George Fisher's fourth child and Richard Pitts.
As they say in America - go figure!
Darcy