Carlins Cairn seems to be the current name of the mountain, as well as the name of the cairn.
This cairn is perched upon the summit of the Kells Rhynns, and may be discerned at 15 miles distance to the south. Some say it was thrown together to commemorate the burning of a witch - others, that it was erected on the spot where an old female Covenanter was murdered by Grierson of Lag. [...] Yet the foundation of the cairn can boast of a much older date than the persecution under Charles the Second, for it was collected by a venerable old woman, who at one period was the protrectress and hostess of King Robert the Bruce.
He goes on to describe at some length, how the King found himself hiding incognito at the miller's house, and how the miller's wife sussed who he was, kept him safe, topped him up with honest peasant food, and concealed him when his enemies turned up. (from 'Unique Traditions Chiefly of the West and South of Scotland' by J G Barbour (1886).
A carline is a Scottish word for a woman, particularly an old one, it's not very flattering and was (according to the OED) 'applied particularly to a witch or one charged with being such'. And from there it's not a huge leap to the similar word cailleach, and maybe the whole mountain can be hers then. It's the first of November today, so the first day when she'll be taking charge from her summery alter ego up there.