by Kelly Barnhill
A baby is taken from her screaming mother to be left in the woods for the (make believe) witch in the annual Day of Sacrifice. The (very real) witch rescues an abandoned baby and feeds her starlight on the way to finding her a new, loving home. Except that she accidentally feeds the baby moonlight and enmagics her, so she must raise the magical child herself with the help of a tiny dragon and a swamp monster.
This book was lighthearted and fun, but it still dealt with big themes like love and family, hope and sorrow, and even death.