I have made some updates to my family tree. A relative in Australia (Jan Vincent) gave me the details of immigration to Australia for George and Harry Mercer, and then Janet, Agnes and Christina Mercer.
Knowing now that they didn’t emigrate from the UK until 1910 and 1912, I looked for the family on the 1901 and 1911 Scottish Census records. I found most of the family living in Torryburn, Fife in the 1901 census and in Dunfermline, Fife in 1911 census.
In both census entries there are relatives included, presumably living with the family. In 1901 Janet Mercer’s mother Janet Kilgour (nee Barclay) was living with them. George Kilgour is on both entries, he is Janet Mercer’s nephew. I’m yet to track down the niece from the 1901 entry – Jessie Kilgour.