Start with high-confidence renaissance for kids books, then narrow by subgenre or adjacent topics.
Leonardo
Serge Bramly, Sian Reynolds
The Renaissance: a Very Short Introduction
Jerry Brotton
What Was the Renaissance?
Roberta Edwards, Who HQ
Magnifico
Miles J. Unger
The Renaissance in Europe
Lynne Elliiott
The Innocents of Florence
Joseph Luzzi
Leonardo's Shadow
Christopher Grey, Christopher Peter Grey
Leonardo's Brain
Leonard Shlain, Grover Gardner
The Renaissance Thinkers
Diane C. Taylor
Leonardo Da Vinci: the Renaissance Man
Dan Danko, Lalit Kumar Sharma