I'm not sure the Isabella Shand who married Peter Copland is your Isabella Shand - what evidence do you have for this?
I think she is more likely to be the Isabella Shand or Mackay who died in Elgin in 1867, widow of John Mackay, crofter. Her death was registered by her son-in-law, Roderick Bremner, and gives her parents as William Shand, farm overseer, and Margaret Shand (ms Young).
I can't obviously find the marriage of Isabella Shand to John Mackay, but all their children that I can find were born in Ross and Cromarty. I can see Isabella in 1841 in Avoch:
Burnside of Killen
Isobel Mackay, 45, farmer, (outside census county)
John Mackay, 20, Ross and Cromarty
Isobela Mackay, 20, Ross and Cromarty
Sarah Mackay, 15, Ross and Cromarty
This may be her in Rosemarkie in 1851:
Isabella Mckey, 64, Dravey (sic), Moray
By 1861, she is with her daughter and son-in-law in Elgin:
BREMNER, Roderick, Head, 43, Quarrier, Ross and Cromarty - Knockbain
BREMNER, Sarah, Wife, 38, Ross and Cromarty - Avoch
BREMNER, John, Son, 12, Scholar, Ross and Cromarty - Ferintosh
BREMNER, Daniel, Son, 10, Scholar, Ross and Cromarty - Ferintosh
BREMNER, Margaret, Dau, 9, Scholar, Ross and Cromarty - Ferintosh
BREMNER, Isabella, Dau, 6, Scholar, Ross and Cromarty - Ferintosh
BREMNER, Sarah, Dau, 4, Scholar, Ross and Cromarty - Ferintosh
BREMNER, Alexander, Son, 3, Morayshire - Elgin
BREMNER, Jane Ann, Dau, 1, Morayshire - New Spynie
MCKAY, Isabella, Ma-Law, W, 75, Morayshire - Drainie
Ruth