Ginny Weasley was NOT one of the seven people who took Polyjuice Potion to become Harry. The seven Potters were: Harry, Ron, Hermione, Fred, George, Fleur Delacour, and Mundungus Fletcher. Ginny stayed behind at the Burrow while the others escorted Harry to safety. Mad-Eye Moody was the protector who organized the mission but did not take the potion himself.