Or at least related to her
. They have a similar style with long silvery hair, long Victorian dresses, size, speech manners and personality. They also have very tragic pasts consisting of rejection and the ones they loved having died. Shizuma is emotionally broken because her past lover is dead, Suigintou because no one, not even Rozen who she loved so much, really cared much for her most of the time. Both worked or try to work themselves up to a leading position to prove they are worth more than anyone else and can be very forceful doing so. Also, Suigintou is assosiated with crosses and the moon, and in the second opening of the Strawberry Panic!
anime, Shizuma is seen from the back, facing the moon and standing next to what may or may not be a very very big cross entangled with vines, black feathers flying over the screen.