My 21 month old really enjoys these books. They have the same kind of appeal as Shirley Hughes. He loves seeing other children doing things that he enjoys too (feeding ducks, swinging, etc.). The text is the right length to hold his attention and is well-written. Plus, this series is pretty much the only one I've found that features non-white children doing everyday, normal things in Britain. All other picture books I've found with non-white *main* characters are either set in a foreign country, or are tales of hardship/ exclusion/ difference in some way. That's pretty sad, in 2014.
My one year old son loves this book. The pictures are delightful and the text simple. My 3 year old has enjoyed reading it too. It's great to use to develop language and communication through the pictures.