You could file this alongside Betsy and the Great World and Our Hearts Were Young and Gay--young girl travels to Europe on her own. She explores France, meets interesting people, and in the process, finds herself.
And yet, it is completely different. Set and published in the 1950s, Sally Jay is a very different kind of heroine. There's sex (gasp!) and lots of alcohol and some unsavory characters. There are times where slapping her seems like the right approach to take. At the same time, you can't help falling in love with her exuberance.
The writing sparkles, and includes one of my new favorite closing sentences:
"It's the end, it's _end_. .! It's the last word.
It's zymotic."

Definitely recommended--and amazed that none of my goodreads friends have read this charmer.