http://www.si.com/planet-futbol/2015/07/05/usa-japan-womens-world-cup-fi...
Carli Lloyd won the Golden Ball as the best player at the 2015 World Cup in Canada in helping the US claim its 3rd Women's World Cup title. Lloyd notched a hat trick inside 16' of the 5-2 championship win over Japan.
There are currently no women on US currency. Carli Lloyd fittingly wears the #10 for the USWNT and thus it is only logical that she be placed on the $10 bill.
Obviously Susan B Anthony and Harriet Tubman among others are more than worthy for the honor as well. Put one of them on the $20.