Jack ...
It's strange that they labeled it as a competition. At that age children are just learning how to see the world ... especially the world of nature. This is the kind of assignment that can allow her to see the world around her in a whole new way. Standing back, but only giving her the encouragement to go for it is like handing her a gift. What fun !
Take the stress out of the whole thing and just enjoy the time you share with this project and you will have a ball. Children have a way of seeing the world without our filters. It can really be quite exciting.