This'll be a review for Rebecca's whole series, which I'm giving a 3.5, rounded up because I ended up really liking her as a character.
Rebecca's series is set in 1914 and stars a young Jewish girl, daughter of Russian immigrants. So there are overarching themes of cultural and generational differences throughout, and probably the most coherent storyline to cover all six books in an American Girl's series that I've read. (Rebecca wants to be an actress, her family wouldn't approve, etc.) There are weightier issues, like unions in the sixth book and the still sadly relevant issue of how to deal with a culture that assumes Christianity is the norm. And there's Coney Island and making silent movies, so Rebecca has a very exciting time of it. She's a great character.