Roll out the red fondant to 1/4-inch thickness. Using the large circle stencil, cut out the red circles with a sharp knife. Store any extra fondant in a ziptop plastic bag so it won't dry out.
Roll out the blue fondant and cut out the blue circles with the smaller circle stencil. Once all the circles have been cut out, store the extra fondant in a ziptop plastic bag.
Trace the W-shape onto the yellow sugar sheet with a black edible ink marker*. Add the inner lines of the Wonder Woman shape.
Cut the W shapes out of the sugar sheets* and peel the plastic off the back.
Dampen the center of the red circle with water and place the blue circle on top. Lightly coat the blue circle with water and place a W on top. With the reserved 1/4 cup frosting, pipe five or six dots of frosting on the red circle, and attach the white star sprinkles. Repeat with the rest of the shapes. Let the fondant toppers dry completely before adding them to your frosted cupcakes.
You can find edible ink markers at most craft stores, and sugar sheets can be found near the fondant at most craft stores.