Just checked out some truly excellent books from the library to read to my 4-year-old:
Adèle & Simon by Barbara McClintock (things to find), The Marvelous Now by Angela DiTerlizzi and Lorena Alvarez Gómez (rhyming & positive encouragement about mood regulation), and Forts by Katie Venit & Kenard Pak (lovely ode to children's forts).
I had a wonderful reverse-Magritte moment reading Adèle & Simon where Simon loses his drawing of a cat and my kid pointed out one of the actual cats in the image. I said "No, that's a cat, we're looking for a drawing of a cat," before realizing that technically we were looking for a drawing of a drawing of a cat, and the thing my kid pointed to was indeed a drawing of a cat, just not in that category relative to Simon's frame of reference...