According to the IGI at
www.familysearch.org there is no Margaret Cumming born in Boharm around 1863 to parents John and Isabella. There is, however, a Margaret Cumming born in Drainie on 29 November 1863 to John Cumming and Isabella Bremner.
This couple were married in Boharm on 22 November 1846 and also had
Isabel, born 25 April 1847 baptised 8 May 1847 in Mortlach
James, born 11 November 1849 baptised 3 December 1851 in Boharm
Alexander, born 11 baptised 21 December 1851 in Boharm
Charles, born 27 December 1853, baptised 22 January 1854 in Boharm
John, born 30 August 1857 in St Andrews-Lhanbryd
According to FreeCEN
http://freecen.rootsweb.com/cgi/search.pl they were not in Boharm in 1861. Isabella, with Isabella Jr and James, was in Tanzie in Boharm in 1851, without John. One John Cumming, farm labourer, aged 38, born Elgin was working at Old Duffus. Whether or not he is the right John I cannot say.
In 1881 there is a family in High Street, Elgin, consisting of John Cumming, 59, farm labourer, born Mortlach; wife Isabella, 59, born Boharm; Son John, mason, 23, born St Andrews-Lhanbryd; daughter Maggie, dressmaker, 17, born Drainie. No matching James, Alexander or Charles anywhere in the northern half of Scotland.
LIBINDX at
http://libindx.moray.gov.uk/mainmenu.asp says that John Cumming, husband of Isabella Bremner, died on 12 January 1891 in Elgin. It doesn't say when Isabella died.
All this is from free online transcriptions (except the 1881 census), so you should check the original census records and John's death certificate at
www.scotlandspeople.gov.uk just in case there is an error. You should also be able to find Isabella's death certificate there as well.
