Illustrations by George Porter, though the cover is by a different artist.
I can't find credit anywhere though the signature on the front looks like
Robes or Rubes.
I remember reading this when I was young and wishing I had a twin. Later, as I grew up, I half hoped I'd have twins that I could name Mitch and Molly (after my favorite American Girl doll).
I liked the sibling interactions in this book since we haven't seen that much. Beezus and Ramona are the only siblings we've seen (besides the older ones in Cleary's young adult books), and they had a different dynamic due to the age gap.
Mitch and Amy don't seem to get along much, but after they face the same bully alone and then together, they start to realize how important they are to each other. I really liked seeing how the bully issue was handled in the 60s.
Each situation the twins found themselves in was interesting and often amusing. For a standalone book, the depth of character development is outstanding.