By playing at art, she develops fine motor skills, learns about the elements of art through experimentation, and learns to clean her paintbrush before dipping into the next color.
Painting with a preschooler requires a lot of patience. There will be mess. And while it seems like making a mess is the little one's objective, as long as most of the paint is staying on the paper, the grown-ups need to stand back, be patient, and know that our little ones are able to see the world in a way we have lost.
Every child is an artist. The problem is how to remain an artist once he grows up.