Duffus In Elgin c. 1800 - 1900

If anyone can help with information relating to my ancestors then please get in touch. Here is what I have so far:
Generation 1:
Alexander Duffus married Helen Watson on 23/08/1806 in Elgin. Alexander, a cabinetmaker, died on 21/10/1865 in 43 South College Street Elgin.
Helen Watson died on 19/07/1858 in 13 College Street, Elgin.
They had at least two children. Those that I know of are Isobella Duffus and Sarah Watson Duffus.
Generation 2:
Sarah Watson Duffus married Alexander MacKenzie / McKenzie, a taylor. Sarah died on 25/06/1875 in 35 North Beck Street, Bishopmill, Elgin.
Isobella Duffus married David Ogilvie, a gardiner, and died on 22/10/1894 in 19 South College Street, Elgin.

I am slightly confused however as I have found a record from the Grant Lodge database which states that David Ogilvie married Helen Watson Duffus who died on the same date and location as my information for Isabella??

I also have a couple of grave references but they don't mean much to me. They are EC 561 and EC 577.

Any information, no matter how small, would be very much appreciated.

Thanks,

Robert.