Well u got some help Pat & will probably get lots more, off hand I do not know of one that's free but if u go to emblibrary their flowers r $1.00 right now & I bet u will find sunflowers there.
Under this link go to "designs for sale" then halfway down on the left you will see a sunflower, click on it and there is a free sample for d/l; http://www.embroiderweb.com/