However, these are my thoughts: if they want to paint the sea turtle, let them paint the sea turtle! Young as they are, I know that if you give them a chance, along with the right materials and tools, preschoolers are very capable!
Obviously, to create this sea turtle they would not be painting with acrylic paint on a 16" x 20" canvas. I altered the project just for 4- and 5-year-olds.
The turtle was a painted paper collage cutout that would be attached to their sunlit painted ocean. That way they were able to paint the starburst shape that is so prominent in the painting (this step was important to them) as well as create a unique sea turtle painting that was super FUN!
We decided these paintings were even more awesome than the original canvas painting!
Notes about copying art: We always encourage kids to draw what they see in their world, which is why all children create personal symbols for common subjects such as houses, trees, faces, hands, etc. It's easier than recreating these things in a new way every time we draw them. However, when kids want to draw or paint from artwork, they abandon their symbols and attempt to create "real" art in the artist's style or in their own style. This is how the Masters studied art; by studying and re-creating the masterpieces (they spent a lot of time in art museums). I think re-creating artwork is a valuable art experience for both children and adults, and I plan to offer this activity as a Painting Challenge in Summer Art Camp 2019, Session 1. Interested? The "Art Challenge" ART Camp starts June 24!