I finished sewing my Granny's knitted squares together! I am a bit worried about the obvious stitching. This is due to the amount of wool of each colour available rather than a choice so I hope she likes it.
I'm not sure the decision to crochet around all the squares in order to make the sewing together really worked as easily as I hoped. As you can see, not all the squares were exactly the same size, and I thought having edges of a consistent wool and easily identifiable loops would help pull it together. I think the lesson here only used tried and tested techniques on other people's projects!