I picked up Hubble Bubble Granny Trouble by Tracey Corderoy with illustrations by Joe Berger because the grandmother on the cover looked like fun. It turns out, she is.
Hubble Bubble is a good example of a picture book in which the text works very well with the illustrations. The word witch is never used. We get that totally from the illustrations, where it is obvious that Granny is a witch.
More importantly, though, she is a vigorous, healthy, even kind of hip grandmother witch. No sign of creaking joints. No hints of cognitive loss. No aging jokes. No aging sadness.
She's pretty unique, and not just because she's a witch.