It is interesting that in this recipe, I used the "Scottish finger" mixing method just as she did and it really works!
The recipe says:
"In Scotland it is said that the best shortbread is mixed with the fingers and that each woman's fingers lend something distinctive and special to the finished cookie."
An added note in this recipe states that:
"In Canada, the sugar in the shortbread is sometimes replaced with an equal weight or 6 Tablespoons of firmly packed light brown sugar for a "richer" cookie." That's interesting because I'm thinking Mrs. MacDonald may have used the brown sugar in hers. I'm going to give it a go the next time I'm tempted to make cookies. These were very easy and light tasting.