Anne, thanks.
Yes, I saw there was a Dennyloanhead on the map and guessed it was that. The OPR says only "Loanhead Congregation".
Apart from the 1851 census pointing me in the direction of Denny / Dunipace, I wouldn't have had any idea where to look. Mary Bruce, born around 1770, married a farmer, James Thomson probably around 1790 - I can find no record of it. They had a number of children in Bathgate between 1791 and 1816. I'm hoping the OPRs, if they do become available online at the end of January, might provide a bit more information - for example witnesses at christenings.
I've been doing some intensive hunting on
www.familysearch.org and have found more information about the family of Bruce of the Nile.
His half-brothers by his father, David Hay Bruce's second wife Agnes Glen between about 1737 to 1749 were, according to a submitted IGI record:
Alexander, David, Thomas, William, Robert, Elisabeth, Agnes, and an unnamed boy. William had a daughter, Mary Bruce, who could well have been born around the time of my Mary Bruce. I don't know the name of her mother, but I came across a genealogy including her, published by a direct descendant of hers, so she's probably not the one (I'm waiting to hear more details).
So it's looking more like my Mary Bruce was the daughter of William Bruce and Janet Newlands, who married in Falkirk in 1769 - and not of the William Bruce who was the explorer's half-brother. As well as Mary and Isobel (1771) in Dunipace, they had Ann (1774) and two unnamed boys in 1778 and 1780 - these last three christened in Denny.
They were evidently part of a large extended family, and as I said, fairly mobile. Some of the children were christened both in Dunipace, and at the Saint John Street Associate Session, Stirling on the same day. I probably need to start looking at land ownership, next time I'm in Scotland. There is a book, published 100 years ago by a John C. Gibson, "Lands & Lairds of Larbert & Dunipace Parishes" that some libraries might have.
By the way, I got two of those possible grave identifications wrong.
BRUCE, James 1803/1812
BRUCE, Margaret (nee Henry) 1803/1812
these would probably be the James Bruce and his wife Margaret Hendry who married on 17 JAN 1777 in Airth, according to an IGI extracted record.
I discovered that James Bruce, the son of the explorer, married an Elisabeth Spicer. They were the parents of Elisabeth Cumming Bruce.