William - I didn't find them in the 1911 Census, certainly not together (apart from Elizabeth who was married in 1907), that would have been too easy! But armed with the print out of this thread, I will be going to ScotlandsPeople for more thorough checking. It has also proved that I need to keep better notes of the searches I have done
Kay - as Monica says the Montgomery family you found in Old Monkland look very interesting . . . do you know where they were living in 1891? The birth certificate I have for Elizabeth (27 Feb 1891) has Jeanie Montgomery giving birth at 13 Wellwynd Street, Airdrie. Also, one thing that might be worth mentioning, Jeanie was illiterate, marking an X on both Elizabeth's and Annie's birth certificates. On the extract you posted from Hugh's 1877 birth certificate I see that Mum Elizabeth signed her name - do you think it's likely that Mum could write whereas her daughter couldn't, unless she had, what we would call today, learning difficulties?
Also, looking at the family there is a Janey age 14, b. in Ireland which would tie in with the 1891 Census where James Brown, 32, slater, b. Edinburgh, is living in New Monkland, Airdrie, with Jeannie, 21, b. Ireland and 1 month old Elizabeth b. Airdrie. The age doesn't quite add up but if the Hugh and Elizabeth were married in 1868 (can't quite read it) and Janey was born after they were married (!) that would probably make her born 1869 - same as my Isabella. What do you think?
More confirmation comes from the 1911 Census when Elizabeth is married, which gives her place of birth as Airdrie, Lanarkshire - the given names of her first two children were Isabella Galbraith Brown and Jane Montgomery (called Jeanie on 1911 Census). I think there is a Scottish naming pattern, can you draw any conclusions from these names?
I am still floundering a bit here but I have lots to work on - many thanks to all!