1/ When writing a picture book biography, it's not enough that your character does cool thing. What character traits drive them to do those things? Why, why, why?
A few archetypes to consider.
(Obviously humans are more complex than this. Humor me...)

2/ The Creator values curiosity, ingenuity, and perseverance.

3/ The Sage values understanding, perspective, and wisdom.

4/ The Caregiver values service, kindness, compassion.

5/ The Rebel values liberation, justice, freedom.

6/ The Jester values humor, enjoyment, authenticity.

7/ There are more archetypes than this, and some of the examples I used in this could fall under multiple archetypes.
The important thing when writing nonfiction is to keep asking WHY. Why do people do what they do?

When the author understands a person or character's motivation, the reader is more likely to feel it, too.

/end/