If you're looking for a "one naptime" project, (yes, that is a legitimate measure of time in my world) here is one (unless you have all boys, then this one might not be for you).
You will have to get the stuff ahead of time (or you may already have some laying around). Various colors of fabric/felt, clips, scissors, fabric glue.
Assemble flowers using glue.
And there you have it! Oh, and repeat as necessary (these are basically disposable the way we lose hair clips:).