Monica
Yes, Helen's mother was called Margaret too - no suggestion of any middle name. I have the family in the 1861 census in North Berwick (James, Margaret & their 2 children Helen 13 & William 6). This means Margaret would have been 23 at the 1871 census. At that time Margaret was married to David and living at 13 Potterrow, Edinburgh. He was away at the time of the census.
Now that I am home, I've been able to look up James Logan's service record.
James Logan was born in the parish of Govan, near the town of Govan in the County of Renfrew. He attested for the Regiment in Glasgow on 24 January 1873 aged 17 years 9 months. He was a tailor to trade. 1783 Sergeant James Logan was discharged on 2 May 1864 after 21years and 9 days service aged 39 years and 1 month.
12 years 53 days were served abroad.
Ionian Islands 2.18 years
Gibraltar 4.61 years
Crimea 263 days
East India 5.26 years
These dates suggest he was born April 1825 in Govan
Whew... I hope this is of some interest/help

Magian