Hi Geordielass
I have now seen your other postings and see that you already have Mary and children in 1891. I've spent a couple of hours rooting around in the 1871/1881 etc. but can't find anything conclusive.
Going on the assumption that William Haughan was born Nov 1881 (and assuming that he was a full term baby) it would seem that Mary conceived around about census night on 3 April 1881. If this were the case then I would expect to find John TAYLOR (if he were the father) not far away from her (she was in service at Bowness?). However, the 1891 census leads us to believe that William was 8 ie. born c1882/1883 as you first thought. It is not unusual for ages to be out on census returns (1 or 2 years is never worth worrying about) but I now wonder about the accuracy and source of your cousins information.
You say you have a birth certificate for a John TAYLOR but can't be certain that it is the correct John TAYLOR. Perhaps it might be a good idea to try and follow his mother - ie. did she have any other children and, if so, what became of them. Did she later marry? Does she appear in any census returns?
With regards to this John TAYLOR whose birth certificate you have - have you checked the census returns to make sure that he doesn't crop up later. Can you be sure that he didn't die - burial registers etc..
The marriage witnesses - HAUGHAN and GATE. Were they related? Interesting that their firstborn may have been named after the witness William HAUGHAN.
And who were the DEVINE visitors on the 1891 census? I have noticed that they come from Wallsend, like the BEATTIEs, so may be related that way?
Maybe it would be a good idea to check out the births/baptisms of all the TAYLOR children just in case there is something in those records. Unlikely maybe but who knows what will turn up. Sometimes births are registered by other relations - I have one registered by a grandmother!
And, going back to the original question, there is always the possibility that John's death was registered by a relative. If it is within your budget, I would get the death certificate. Again, you never know it might have been accidental and if so there would have been an inquest and, possibly, a newspaper report.
I can't think of anything else right now. Not really of much help I know but hope you find it of some interest at least.
Best wishes
Casalguidi