In 2001, I was eleven years-old, and one of my favorite movies was Legally Blonde. Elle Woods (Reese Witherspoon) was the quintessential “girly girl,” and the film was spent reifying this again and again to ultimately pronounce the heroine’s independence as a result of her devotion to fashion, make-up, and all things pink. The text is ostensibly post-feminist drawing from Angela McRobbie’s definition.* It frames hyper-consumerism as a mode of gaining female independence in a capitalist society. In many ways, Legally Blonde is problematic because of this emphasis on hyper-consumerism, but the text also presents a strong female network. By the end of the film, Elle demonstrates to her ex-boyfriend—he broke up with her because of her waning “seriousness” — that her “girly” appearance and optimistic attitude does not mean she lacks intelligence or confidence. She graduates at the top of their Harvard class and earns a prestigious position at a law firm run by Professor Stromwell (Holland Taylor), a female teacher who had previously looked down on Elle for her “girlish” proclivities. 
SOURCE: http://www.hautetempered.com/why-we-love-elle-woods/ – “Why We Love Elle Woods”
Yes, Legally Blonde has its issues—which we’ll revisit shortly—but it draws attention to the deployment of “girly girl” as intended toward disempowerment and judgment. In my brief Google searches** of the terms “girly girl” and “tomboy,” I found both have been historically deployed as criticisms. “Girly girl,” deriving from “woman’s woman,” was often deployed as a means to criticize someone as too feminine. The label of “tomboy” was deployed predominantly as a means to denigrate a woman for acting rudely or boldly, out of “place.”
We all label. Our identities are fluid, and that deserves acknowledgment, but labels help us talk about ourselves to one another. They’re not perfect, but they’re necessary, and we should strive toward respecting others by using labels preferred by whomever we’re addressing. I don’t have an issue with a woman’s choice to self-label as “tomboy” or “girly girl,” but I do take fault in either term used to define the superiority of one over the other. As a young woman growing up in the 1990s, I have too often heard the argument, “I’m not like those girly girls. I like guy stuff.” Especially in the gaming community, this argument resurfaces often.
And I think post-feminism and the representation of women in the 1990s in texts like Sex in the City and Legally Blonde have a role to play in why this comparison —“tomboy” versus “girly girl”— occurs. As McRobbie explains succinctly, the post-feminist texts of the 1990s sexualized women in a way to make it look like their exhibitionism was sexual independence. Something like: “I want to have my half-naked and photoshopped body on a billboard selling male deodorant because I’m sexually independent.” Sexual independence is great. I hate wearing bras. I hate that I can’t talk about my period when I feel like it. Breasts should be allowed out in the open, because why the hell not? But in advertisements targeted toward men that showcase female nudity, we should question who is ultimately given agency to speak.
SOURCE: Annoyed Critic – “I hate Carl’s Jr.’s TV Commercials”
Gender is a key marketing strategy, especially in television, and most of this kind of marketing is guesswork. Amanda Lotz does an excellent job of explaining this in her book Redesigning Women* In the age of the post-network*, now post-television, identifying key psychographics*—women who like edgy humor, women who like games, women who like space aliens, etc.—is the principal strategy in generating an audience from a mass that now consumes media asynchronously and through a variety of media. This strategy is the reason why we started with Lifetime, the sole cable network targeted toward women, and then WE and Oxygen later became viable competitors, although they target different segments of the female demographic. The marketing strategy of television has come to recognize that people are different. Not all women will enjoy the programming of Lifetime or even WE or Oxygen. While television has recognized more difference, labelling it distinctively has become vital toward selling difference as brand. Penny of the Big Bang Theory and her stereotypical “girlishness” define the stereotypes of nerdiness proffered by the show’s other protagonists by comparison. Together, they attempt to attract an audience of “nerds” —and a general audience in its juxtaposition of the “nerds” and the so-called “normies” —by loudly proclaiming, “HEY! LOOK, NERDY STEREOTYPES. ISN’T THIS COMICALLY FAMILIAR, EVEN IF STEREOTYPICAL?” 
SOURCE: HerBeauty – “Penny Geek Chick (Big Bang Theory)”
One reason I believe so many women of my generation, at least in my personal experience, reject this stereotype of “girlishness” is because the media has foisted the stereotype on its audience as a sign of empowerment, but rightfully so, we don’t—or at least when the character does not move beyond stereotype—buy into it. While this rejection is empowering, what I would like to leave with you is a bit of didacticism. This stereotype of “girlishness” should not be mistaken for the reality of girls, and defining oneself as a “tomboy” or a “girly girl” isn’t problematic, as long as the labelling isn’t done to denigrate other women at the behest of elevating “guy stuff” or “girl stuff.” What is that “stuff” anyway? I love Hello Kitty, but I can cuss out a n00b on League of Legends with the best of them, and I don’t think this makes me any less or more a woman.
**Wikipedia’s entry on “Tomboy” and “Girly Girl” and a dictionary definition
*Angela McRobbie’s “Post Feminism and Popular Culture” *Amanda Lotz’s Redesigning Women *Amanda Lotz’s The Television Will be Revolutionized
*psychographics: “analysis of consumer lifestyles to create a detailed customer profile. Market researchers conduct psychographic research by asking consumers to agree or disagree with activities, interests, opinions statements. Results of this exercise are combined with geographic (place of work or residence) and demographic (age, education, occupation, etc.) characteristics to develop a more ‘lifelike’ portrait of the targeted consumer segment.” – Business Dictionary
Motley Omelette 