Thank you all for all your input/info/attention. So very grateful,

We are not sure if Noel lived with the family at the same time although he had to have some imput .. Lol..
I've sat with hundreds of records in Liverpool libraries and my biggest conundrum is how reliable Kelly's were in comparison to the electoral roll. Noel Kavanagh was found when Ms Cavanagh left the premises according to Kelly's records for a number of years after Ms Cavanagh left. She definitely did not marry him but took his name for obvious reasons... However, the electoral records show a different name - Galvani.. Is it really worth pursuing Galvani given that the name is soooo different?!?
Cavanagh is what is documented on both birth certificates and a job of 'self employed' or acetylene welder (shipyard) has been written (yes, I've been to the maritime records and nothing is listed under his name or job description anywhere including all shipyards in the area or with any trade unions).
As I say, we don't know a great deal about Noel other than he was older than Ms C. We know he lived in wren street during 1942 (at least) to 1949.. we know that he fathered two offspring with Ms C. We know that he baptized his offspring in a Church of England church so we can assume/presume he may not have been Catholic although as they weren't married, this may have been a problem.
We know that wren street has gone but don't know exactly when.
I have looked briefly at Galvani but it's so different from Cavanagh that I'm worried that I want to make it fit when it's probably a different family entirely.
The decree absolute isn't necessary I don't think. It's almost definite that they were not married, but I do appreciate the suggestion. Thank you 😊
Again, thank you all so much for your input.
I have fingers and toes crossed that something new turns up soon... And of course I'm always still very much open to any more suggestions from you 😊