hello monique,
the easiest way to find your great grandmothers marriage and death certificates is to use the scotlandspeople website. it is pay to view and costs £6 for 30 page credits, but as you have some of the info you need to find them already, you should have enough credits left over to search for other certificates too.
e.g if you enter the search criteria for their marriage (shown below) and view the results, this will cost 1 credit and then if you open the certificate to view the details, this will cost 5 credits. you can then . image and also print it if you want to. if you do this, it has cost a total of 6 credits from your 30 that you paid for.
KENNETH SUTHERLAND
Spouse: MARGARET WATT
Marriage: 11 FEB 1860 Monymusk, Aberdeen, Scotland
also i mentioned in an earlier posting that the scotlandspeople website also have a possible match for margaret's death certificate:
Scotlandspeople have one match (death records) for margaret sutherland other surnames watt in cluny, aberdeen in 1911 aged 83 years.
i didnt look at the actual cert, so cant be sure it is the correct one. although age almost fits with age at 1881 census and area where they were living at time of 1881 census also matches...
if it is the correct one, it would give you her both her parents names and also her mothers maiden surname if known by person registering her death.
there is also 1 other match (death records) for margaret sutherland other surnames watt in aberdeen, but i didnt look for district because she died in 1953 aged 81 which would make her born c1872 snd obviously isnt the correct one.
again if you use the details for the one in 1911 aged 83 years, it should only cost you another 6 credits and hopefully have a lot more information to work with.
all this should only cost 12 credits in total out of your 30, leaving you a further 18 credits to do other searches.
i hope this helps you a little.
kind regards,
Lorna.
p.s sorry, i don't know if the Ballater and Kemnay Watts are connected and don't know how you could find out.