I loved this picture book that we found at the library, Summer Birds: The Butterflies of Maria Merian by Margarita Engle. It is a true story, a picturebook biography about a woman who lived centuries ago and was one of the first true naturalists. She discovered that caterpillars turn into butterflies, as it was common belief at the time that butterflies and caterpillars were two separate types of insects.
The pictures are stunning, and have that a botany-for-kids feel (like if these posters were made for kids), and perfectly align with the narrative. I had never heard of Maria Merien before but when looking her up on Wikipedia, I found that she illustrated her first botany book at age 28; quite impressive for the 17th century and being female.
This is a wonderful companion book for science and nature lovers, studies in female scientists and game-changers, and just an all-around beautiful picture book. I see a butterfly project in your future!