Just the fact anyone ever coined the phrase "career girls" proves they were a real anomaly.
Peggy Olson is the resident career girl on Mad Men. She differs from the secretaries in the obvious way: she holds what's considered a man's job. Even Joan, who is unequivocally competent and clearly likes her work, is really just a queen-bee secretary. The only comparable woman is Dr. Faye, the market researcher in her late 30s who pretends to be married but is not. So how strange was it to meet a Peggy in the mid '60s?
It depends who stopped her in the ladies' room. In Sunday's episode Megan, the slightly younger secretary, tells Peggy she's doing "quite well" for 26, suggesting, with a boyfriend and career, she has it all. Then seconds later, the near-in-age Trudy Campbell consoles her with "26 is still quite young," insinuating she's not a lost marriage cause. Yet.
The median age for women to marry in 1965 was 20.6 (it was 25 in 2008), so at 26 she was moving from a single girl to an unmarried woman. But 1965 was a crossroads, and she could see herself two ways — someone to be pitied or admired.
When she confesses to Don, "I know what I'm supposed to want, but it just never feels right, or as important as anything in that office," we see that she's not sure if she's an object of pity or praise yet. But she's betting on praise.