Character Analysis
If you look up "loyal" in the dictionary, you'll see a photo of Gretchen Wieners and Karen Smith. They're like a pair of well-manicured puppies, and not just because they have such shiny hair; they'll follow Regina to the ends of the earth if it means staying popular and socially protected.
The Power-Hungry Toaster Strudel Heiress
Gretchen is desperate for Regina's approval, and she's willing to put up with all sorts of ridiculousness and regulations in order to get it. At first, she seems to revel in all the rules that come with being part of The Plastics as she relays them to Cady:
GRETCHEN: You can't wear a tank top two days in a row, and you can only wear your hair in a ponytail once a week. So, I guess you picked today. Oh, and we only wear jeans or track pants on Fridays. Now, if you break any of these rules, you can't sit with us at lunch. I mean, not just you. Like, any of us. Okay, like if I was wearing jeans today, I would be sitting over there with the art freaks.
Cut to Janis and Damian. She's putting cold cuts on his face, and he's doing an impression of Sloth from The Goonies.
GRETCHEN: Oh, and we also vote before we ask someone to eat lunch with us because you have to be considerate of the rest of the group. Well, I mean, you wouldn't buy a skirt without asking your friends first if it looks good on you.
CADY: I wouldn't?
Being able to rattle off all of The Plastics' superficial rules shows that Gretchen's part of the club. Once she feels rejected by Regina, however—after the 1–2–3 punch of not getting a candy cane-gram, being pushed to the fringes of The Plastics' "Jingle Bell Rock" choreography, and ordered to "stop trying to make 'fetch' happen"—Gretchen drops the "Yay, team!" façade a bit and gets real.
She starts spilling Regina's secrets to Cady, and explains to Cady just how rotten Regina really is:
GRETCHEN: If you even knew how mean she really is. You know that I'm not allowed to wear hoop earrings, right? Yeah. Two years ago, she told me that hoop earrings were her thing, and that I wasn't allowed to wear them anymore. And then for Hanukkah, my parents got me this pair of really expensive white-gold hoops. And I had to pretend like I didn't even like them, and it was so sad.
Gretchen isn't the blind follower that she appears to be. (That's Karen's job, but more on her in a sec.) Gretchen realizes that, if she wants to be part of The Plastics, part of North Shore's ruling class, she has to make some sacrifices. Sometimes it's a pair of gorgeous white-gold hoops. Other times, it's her pride.
Let's let Cady explain:
CADY: The meaner Regina was to her, the more Gretchen tried to win Regina back. She knew it was better to be in The Plastics, hating life, than to not be in at all. Because being with The Plastics was like being famous. People looked at you all the time, and everybody just knew stuff about you.
Cady has Gretchen pegged. For Gretchen, popularity trumps all. It's not Regina that she wants to like her; it's everybody. Regina's just the best conduit to that. As long as Gretchen stays in Regina's inner circle, she's popular by association. Once Cady's plan to destroy Regina is complete and she deposes Regina, Gretchen drops Regina like a bad habit and is #TeamCady.
Similarly, at the very end of the film, after Girl World has imploded, we learn that Gretchen's found a new queen bee to follow and has joined the "cool Asians" clique, despite not being Asian. The last time we see her, she's made herself over to look like the rest of the clique and she's gossiping in broken Vietnamese with her girls over lunch.
Gretchen isn't loyal to Regina, Cady, or whoever the queen of the cool Asians is. Gretchen's loyal to power.
Meteorologist in the Making
While Gretchen's a hungry social climber, Karen just wants to look pretty and be told what to do. To that end, she's a realist. She's not the brightest bulb in the box, and she knows it. Check out this conversation she has with Cady:
CADY: You're not stupid, Karen.
KAREN: No. I am, actually. I'm failing almost everything.
CADY: Well, there must be something you're good at.[…]
KAREN: I'm kind of psychic. I have a fifth sense.
CADY: What do you mean?
KAREN: It's like I have ESPN or something. My breasts can always tell when it's gonna rain.
CADY: Really? That's amazing.
KAREN: Well, they can tell when it's raining.
Karen may not be honor roll material, but she has a positive attitude and she knows how to use her strengths—and we don't mean her "fifth sense." We're talking about her easygoing nature and her looks. They're a natural fit for The Plastics.
Regina's happy to have a super-loyal soldier who has the right look, and Karen's stoked to have a support system and to sail through the choppy waters of high school being pretty and occasionally treating herself to Taco Bell.