This icing is meant to go with Chocolate Cake.
The recipe uses hydrogenated vegetable shortening, under the Spry brand name. I’ve commented on the history, use and health considerations of using Spry or its competitor brand, Crisco in an earlier posting. My personal choice would be to use butter, which would probably also give a better taste.

I absolutely love your grandma’s handwriting! Did she attend a convent school?
Mine’s awful!
Hi Emily,
Yes, grandma went to a convent school! How did you guess :)? Her handwriting was very typical of that era, I think.