Catherine Violet Mackison seems to have been the daughter of Francis Mackison and Margaret Glover.
In the 1881 census they were at Ville de Lancaster, parish of Logie, Perthshire (this is possibly in or near Bridge of Allan but when the LDS transcribed the 1881 census they left out all the town and village names).
There are Francis Mackison, aged 59, civil engineer and architect, born Kilmadock, Perthshire, wife Margaret, 47, born Penninghame, Wigtownshire, and daughters Margaret de L Mackison, 13, and Violet C C Mackison, 11. Both daughters born in Stirling.
Francis and Margaret were married in 1866 in St Ninians, Stirling.
Go to
www.scotlandspeople.gov.uk and buy a copy of the marriage certificate. It should tell you the names of all Catherine Violet's grandparents.