I'd just add Jon Muth and his "Zen" series.
We have 21 out of the 26 B Potter books and have found them very viable as my daughter has reached 4. Her favorite is Jemima too! So much so that we had an appliqued T-shirt made for her with Jemima and the fox (and sprigs of thyme and sage, ha).
Danielle, Nick, Gigi ('08) and William (7/11)