Dunno why I drew this.
Amy takes the place of Mario and Sally takes the place of Luigi. Thats because of their size differents. Luigi is bigger than Mario and Sally is bigger than Amy.
This picture really reminds me of the game "Giana Sisters" for the Atari. (Yes, we used to own an Atari. I wonder where it is now, though.) The game was a Mario ripoff with two female characters.