I ended up with a ex-library copy of this book as a kid (probably after a book sale), and I remember loving the book. The story included a quirky but believable family with a single mom who, when offered the chance to create a new art portfolio to get a job that would be perfect for her and her family, has to hand the household over to her oldest son for a couple weeks. Henry finds himself navigating lunches, his brother's fondness for frogs, his little sister's newly adopted cat, and his well-meaning but overbearing great aunt. It's a lovely narrative about family, responsibility, childhood, and growing up.
Henry takes on the responsibility of his siblings so his mom can go back to work. Henry makes some mistakes along the way, but overall he does a great job. If I had a kid, I'd want him to be like Henry. Based on the title, I thought there would be more about the cat. The parts with the cat were funny and adorable.