It's pooey on B-A-B-I-E-S until Junie B. finds out that her new dumb old baby brother is a big fat deal. Her two bestest friends are giving her everything they own just to see him. And guess what else? Maybe she can bring him to school on Pet Day.
In the second Junie B. Jones book, the Jones family welcomes a new member: an unnamed baby brother. But Junie B. isn't exactly pleased about this new development... until her grandmother calls the infant "the cutest little monkey [she] ever saw". And Junie B., of course, is thrilled to have a monkey in the house.
What the book boils down to is a short, humorous story that attempts to teach children the different between figurative and literal language. Children in on the joke will likely find Junie B.'s misunderstanding hilarious, and children who share in her confusion will (hopefully) learn something. And given the "bringing home a new baby" element—which I imagine will continue in the next book of the series—it might also be a great way to get a young child ready for their own new brother or sister.
Definitely recommended for young fans of the humor genre, though I suspect it's a better reading experience for those children with a strong enough grasp of the English language to recognize that Junie B.'s "authentically childish" speech pattern is part of the humor.