I really enjoyed this this story of parental misunderstanding, and so did my son of three. His baby sister is just learning to talk and he was hysterical with laughter at Trixie's attempt to communicate and every time we read it shouts "Aggle Gaggle Flaggle" at the appropriate moment. I think the story is very easy for children of all ages to relate to: that your parents don't always understand you. There are lots of details my son picked out on multiple readings; the photos on the wall of Trixie's parents as backpackers, newlyweds, and then exhuasted new parents; that Americans say laundromat not launderette; the emotions on Trixie's daddy's face depicted so accurately. But fundamentally it works as a strong narrative of adventure, crisis, and redemption told with rhythym and repetition in a way children who are barely old enough to talk can enjoy.
Like all good texts it does work on several levels and from a parent's perspective it is so true and funny I guarantee you will laugh aloud in empathy.