Pretty in Pink
Although the T-Birds are basically interchangeable (we'll trade you a Doody for a Putzie), the Pink Ladies are so different, we only know they're in the same social circle because of their pink jackets. Which, now that we think about it, they barely wear.
The three Pink Ladies, in order of importance (based on our very scientific analysis) are Jan (Jamie Donnelly), Marty (Dinah Manoff), and Frenchy (Didi Conn). Let's compare and contrast these three rosé dames, shall we?
Similarities: They wear pink jackets. They like sleepovers. Uh, that's it.
Jan is the comic relief character. Her trait is she likes to eat and tell jokes. We never see her without a Twinkie, an Oreo, or some other trans-fat laden snack product in her paw. If Grease were a novel—well it would be really boring without the singing—but Jan would probably be described as fat. For instance, Putzie even makes the following comment:
PUTZIE: I also think that there's more to you than just fat.
Um, if Jan is fat, no wonder Hollywood is often accused of fostering eating disorders in young people.
Next up is Marty. Marty's boy crazy. Rizzo describes her as a "one-woman USO" because of all her military boyfriends. She spends the slumber party doing bust exercises. And she hits on Vince Fontaine, who could be her father. Marty would be a grandmother in 2006, listening to Nelly Furtado's "Promiscuous" and remembering the good old days.
Finally we have Frenchy: the girl with a flair for beauty who takes Sandy until her hot-pink wing, by inviting her to a slumber party.
FRENCHY: You know what you need? A night out with the girls.
Frenchy is the only Pink Lady nice to Sandy. Rizzo's hostile. Marty's indifferent. Jan rarely looks up from her Ding Dong. Sadly, Frenchy is subject to one of the movie's weirder messages. In "Beauty School Drop-Out" Frenchy is basically told to stop following her dreams and just stay in school.
While everyone should stay in school, why can't Frenchy do both? She's told to quite beauty school because her pink hair "looks like an Easter Egg." Frenchy is a girl born in the wrong time. Today, she'd be an Instagram sensation.