"Yes, there is a little boy born in her parish with that name in Jan 1892 with the mother's name given as the same, so obviously out of wedlock. But it's not that uncommon a name in that part of the world. Would be a coincidence if it was another child, but there are a lot of those in researching as you've probably all found out..."
There's a (relatively) cheap way of finding out if it is the person you're looking for - it costs £3.
From your description it sounds like you have the Civil Registration Birth Index for him?
If so then it is an easy matter to get a digital image of the actual birth certificate.
The information you will have will say something like:
Name: Babyboy Nightingale
Reg Data: 1892
Quarter: Jan-Feb-Mar
Reg Place: eg Bristol
Volume: eg 5a
Page: eg 154
And this is what you need to order a digital image of his birth certificate.
If you go to:
https://www.gro.gov.uk/gro/content/certificates/indexessearch.asp
and select "birth" and then the year of birth (you can include a range of +/- 2 years).
Then enter the surname and sex. You can also enter all the other details that you know eg first name, place of registration, volume, page etc.
You then hit "search".
It will come up with all the births that match that criteria - if you just enter the name then there will be several, but if you enter all the other info then there will just be one.
If you then click on the name of the person you are looking for you will be given three options for ordering: Certificate, PDF or Digital Image.
You then click on whichever option you want. The cheapest is Digital Image, which costs £3.
This will then take you to a page where you can order a digital image with all the information pre-filled so you don't need to repeat it.
If you then choose to pay for a digital image it is available immediately (although I've found that I need to log out and log back in again to actually see it).
Attached is an example of a birth certificate (this one is from my 3xG grandmother from 1848) that I downloaded this way. It shows that she was born in the workhouse and that her mother was unmarried (although her parents did marry the following year in 1849). The birth was registered by the Governor of the Workhouse.
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"Yet when I look at their father's 10- year discharge papers from 1899, he claims to be unmarried and childless! "
I don't know if I can help much here beyond sharing a similar story, which was really quite sad.
I was tracing a relative and, incidentally, came across a relation called Charles, born in 1879. His father died when he was five and his mother died when he was 15.
He joined the Somerset Light Infantry as soon as he turned 18 in 1898 but then swapped to the Dragoons (a cavalry regiment). He went on to serve in South Africa in the Boer War and then in World War One. After that he joined the Mounted Military Police and he was then stationed in Mombasa, British East Africa (nowadays Kenya).
I think this perhaps gives an indication as to why the armed services were more popular in the past – perhaps they offered structure and support that young men were lacking?
During World War One he was awarded the Military Medal in 1916 and left the army in 1919. He married a woman named Gertrude in 1915 and he never had any children – or so I thought. But it turns out that he had an illegitimate child born in 1907.
In 1908 there was a Maintenance Order made against him and he was required to pay 1/9 per week until his daughter, Kathleen, reached the age of 15.
What really hit me though was that, in the 1921 census, Kathleen's father is recorded as being dead.
Perhaps Kathleen was actually told that her father had died (like it was stated in the 1921 census) even though, in fact, he had later married another woman in 1915. Maybe she went through her life thinking her father was dead when he was actually living in Croydon with his new wife.
Who was to blame for that lie? Did her mother not want to acknowledge to her daughter what had happened or did her father not want anything to do with her? (For context, her mother married another man in 1918 and went on to have three further daughters with her husband)
Either way, that's a terrible situation to grow up in.
Quite a lot of genealogy can end up being about serendipity. There is no way that anybody looking for the biological father of Kathleen would think of looking in the service records of a random soldier in Aldershot barracks.
But, doing it the other way round, I was reading this record of a guy who was awarded a Military Medal and then found out that he also had an illegitimate daughter that he was ordered to pay maintenance for. My DH said that we should add all of this to the tree so that other people can find it and don’t have to repeat the work.
The more I think about it the more I agree with my DH’s stance. If some descendant of Kathleen’s comes along in the future then they can find out who her biological father was.