You're looking for your 2 x g.g.aunt (who never married) on the 1891 census and find she is living with a son Edward (your 1st cousin 3 times removed) in Essex that you didn't know existed. So you go backwards and find his baptism (in Halesworth, Suffolk) which shows a middle name obviously a surname, so you look for a man with the same name in the area they were living to see if there is anyone who could be his father (there was a single man who is a possiblity but no proof of course). You find Edward in 1851 and 1861 lodging with a family near his birth place. In 1861 his mother was living in IOW and working for a Major in the Artillery) and you find he enlisted in the Royal Artillery in 1867 aged 18. Perhaps his mother's employer had something to do with this.
You don't find him again until 1881 when he was living in Woolwich (a sergeant in the Royal Artillery) with a wife born in Govan and a son born in Limerick in 1877. So you look for the child's birth (your 2nd cousin twice removed) and Edward and his wife's marriage (in Limerick). You find them again in 1891, Edward now a grocer, but there are Pension Permission/Examination records for him in 1889 (full records on Ancestry's Fold3 - no I didn't subscribed to that!). As you can't find him in 1901 even though you've found his wife who says she's married, you look for his death which you find in 1902 - so where was he in 1901? Then because you are still curious you look for his son in 1939 where he is living with a wife and 2 children, plus 1 redacted (these are your 3rd cousins once removed) - so what do you do next? Yes you look for the birth of the redacted child, turns out to be a girl, so you look for her husband and then you look for her death to see if she should be unredacted.
Meanwhile on all the census from 1891 there is a child living in Edward's household who is shown as a niece aged 3, she is still there in 1901 with Edward's wife and son aged 13 still called niece, and she is still there in 1911 with Edward's wife and son still called niece. The interesting thing is she has as her middle name the surname of my 2 x g.g.aunt and offspring, therefore, so you decide to look for her birth on Scotlandspeople to see if there is a clue as to why she has the family surname as her middle name. There is no reason, her father was a policeman and married her mother in Portsmouth. The mother didn't even have the same maiden name as Edward's wife, and neither her maiden name or married name was the same, so where the "niece" relationship came from I have no idea.
Is that enough, obviously not. In 1911 still with Edward's wife and son, there are 2 young children listed as visitors, one born in Edmonton, the other her brother born in Ipswich, Suffolk so you have to look for their births don't you? As expected both have a - shown instead of mother's surname. In 1911 you look for an adult with the same name as the little girl and, guess what, you find one living and working as a servant in the same area as the family is living. So are these Edward jnr's children or just random children? Certainly the name of the daughter and the woman with the same name, is not the same as his wife in 1939.
I'm giving up on this family now, it has got totally out of hand.

ps. Edward's son, also called Edward joined the Royal Artillery like his father but no, I haven't looked for his records.