I'm not quite sure what to call the subgenre that Sally Baxter and her ilk belong to (grandmother: Cherry Ames), which is part career girl story, part mystery tale. They're nearly always published by World Distributors, so they have a similar 'look', especially if the dust jacket is intact. Other examples are Vicky Barr, Shirley Flight and Sara Gay. These series feature unmarried girls, but usually from traditional families, with jobs that take them all over the world (Cherry does almost every kind of nursing she can, Sally is a reporter, Vicky and Shirley flight attendants and Sara a model). They're part-time sleuths, as they come across mysteries wherever they go and because they feature in serial stories, they need to do well at their careers for a long time, even if their attention is sometimes divided.
The heroines of straight-up career girl stories, may feature a mystery subplot, but they are much more about depicting the demands of a job for their readers. 'Kate in Advertising' by Ann Barton, Joanna in Advertising by Stella Dawson, and Marjorie Riddell's 'A Model Beginning' and 'Press Story' are some examples from my bookshelves. Somewhat unrealistically, they usually end with the heroine getting engaged and the likely outcome is that she will give up her job for marriage and motherhood. So why do I call them career girl stories? Well, they still work as an intro to the career rather than being about the romance. And I may be over-generalising there. Not all end like that.
However, the serial stories subvert this, most interestingly in the Cherry Ames series, and they're somewhat anti-romantic. The heroines are shown as attractive and likeable, and with plenty of dates on call, but they never say yes to proposals. The audience for these stories is slightly older than 'A Crime for Caroline'
, obviously, although, again, who am I to talk, still reading them, many years after I came across my first Cherry Ames? And that doesn't even consider the influence of Nancy Drew, although sleuthing is her hobby-career (she doesn't need the money, but she does need the challenge). But in the days when the series started, why, going to college was what boys do! (It'll be interesting to see how the new movie handles this).
Sally Baxter, like Shirley and Sara (oh, they all start with S's) is a very English character. (As is nurse Jean, who has four books and two authors to tell her tale, but she isn't published by World distributors). The book which brought this on, Sally Baxter--Girl Reporter and the Holiday Family by Sylvia Edwards, starts off when Sally gets sent on a summer stunt to improve the circulation of her paper, the Evening Cry. The paper pays for a family already visiting a seaside resort (how very British) and voted for democratically to have their dream holiday. This upgraded holiday is then covered by Sally. Of course what she ends up reporting is a series of catastrophes for the first holiday family, who turn against her and go back home until she can uncover who is behind the ir misfortunes and why. (Let us just say that the story is really of its time and leave it there.)
ETA: Related links can be found here.