It's possible Gramma just made them off the top of her head. I did a Rav search to see if I could find the pattern, but didn't, not exactly. Marion Torgerson's is close - enough to give me an idea how to start it, anyway. And I do have a pretty good photo.
Once I've turned in my 50% HoM OWL (or failed spectacularly to do so - 18 rows left!), I'm going to do one of these just to relax on Friday. I'm sure there's a class for which I'll be able to make it work!