Yes you can use challenging vocabulary in a picture book

When I wrote Lauren Ipsum, a children's book about computer science, I used the real words for everything. Words are random anyway so you might as use the ones everyone else does. There are a few puns, eg "Hugh Rustic" teaches heuristics, "Eponymous Bach" names everything after herself, and "Xor" is a colorblind chameleon. I also included a species of animal called the Jargon who constantly spout computer jargon. They are cute in small numbers but will run you over if you let them.

My favorite comment was from a mom who'd read it with her six-year-old. Weeks later she was storing her luggage, putting the smaller ones into bigger ones. The kid piped up and said, "Mommy, that's recursion!".

Kids are smart. It's astonishing what kids can do if you don't tell them it's too hard.

I remember listening to the Lemony Snicket author telling Terry Gross how he plants his favorite obscure words in his super-popular kids' books, in the hope of propagating them to the next generation of readers. That seemed brilliant to me. IIRC, the example he gave was 'eschew', but that might be faulty memory as I also enjoy eschewing things.

I'm in the midst of writing my first picture book.

I needed a release from the general stress of dealing with the cybersecurity challenges, and something for children sounded great.

The world of my book is devoid of computers or complex machinery. Instead, magic exists and just as in real life with computers, people approach it in different ways. Some use it help them prepare better looking and tasting food. Some use it to help others get around more quickly. Some use it to make music or play with pets. Some sometimes let it get in the way of the time with their children.

The core lesson that the book tries to incept is that magic (i.e., computers) should aid in our humanity, not detract from it. The protagonist is a little girl with a blind brother. At first, she resents having to help him with tasks, but throughout the story she learns the importance of helping other people. She has a natural knack for controlling mushrooms, so the book ends with her helping her brother by conjuring mushroom stairs and the like, and he has a secret power of his own that he confides in her. He can get small rodents, like mice and chipmunks, to do simple things for him. Armed with this fact if you reread the story you'll see them in the background helping him out.

I've been researching how to write for children and the biggest area of disagreement seems to be over how complex words can be. For example, most books say to stick to simple "said" words ("she said", "he sung", etc) but they seem to disagree over whether complex words are allowed. I'm willing to do whatever it takes to make the book good, but I'd love to be able to imbue the book with words like "portabello", "oyster", "shiitake" because of how important their role is in the story. I also think it could be a touching way for families to talk about food later at the dinner table and would make kids more friendly to mushrooms; a healthy, sustainable food choice.

Has anyone here made a picture book for 4-6 year olds that can comment?

But using no words whatsoever is also wonderful. Here is "On Top", by Marilyn MacGregor: https://www.amazon.com/Top-marilyn-macgregor/dp/068807491X/r...

I am a strong believer that reading is extremely enriching for the mind. Any additional ways to enhance that experience, in my books, is a win.