Hi Kathy !
On Scotland's People, there is only one Mary Buchanan born in Portree between 1855 and 1860.
Mary was born in 1859.
Her GROS data is 114/01 0029, with a copy of her Birth Certificate available on Scotland's People.
Without seeing her Birth Certificate, I can't be sure this is the right Mary Buchanan, but the dates seem to work OK.
From the 1881 - 1901 Census entries, it can be seen that Mary went on to marry a German national, from Danzeig.
He was called Charles Bottcher - anglicised to Butcher in subsequent censuses.
Charles worked in the Clyde shipyards, and the family lived in Greenock.
They had 2 daughters: Maggie born in 1884 or thereabouts, and Christina born around 1889.
Maggie married Thomas Beckett, and by the 1901 Census, Mary and Charles had a 3-month-old grand-daughter, Amelie.
It will be interesting to see soon how the family was in 1911.
I've done a mini-family-tree of the above on Ancestry - if you would like to see it, let me know your email address or your Ancestry username and I'll send you an invitation to share the tree.
Hope this helps.
Best regards, Paul