Here's how we made the costume.
* red/black/white dress
* leggings (heart patches made of felt and attached with adhesive velcro dots)
* queen cape (optional, but we already had one)
* heart brooch (cut out of felt and glued to pin back
* crown (cut out of felt and glued together; attached to headband with adhesive velcro dots)
Pieces can be sewed or glued in place. I used velcro in case any of the pieces needed to be moved around.