The most definitive symbol of girlhood is a bow. Place the bow on the baby and there is no doubt that children born to women and named the baby boy that bounces. The same could work for a skull tattoo for girls. Place a giant pink bow on the skull's head, positioned in a beautiful way. You also can place two smaller arcs, one on each side of the skull. Of course, you always can use another color other than pink. eg black, make a bow your favorite color. the more you use a lot of colors will look attractive.