the title character's name is Rose

[Lorraine]

Rose is one of four title characters of a series of connected novels; the other three novels are also names of women, and they're all written by the same author. The setting is in the past, but not 'once upon a time', possibly WWII, but the war isn't central to the story, as far as I remember. Rose, I'm thinking she's a Russian (or European) princess in disguise, of a noble family but poor. She has long, beautiful hair, and when, at one point in the story she gets it cut off, I was shocked. There's some element of mystery/suspense involved, and she meets a young man somewhere in the plot; she's in some degree of danger, but the novel ends well - not 'happily ever after' well, but the good people are alive and well, the bad guys are dispatched in some way. I read it in the late 2000s/early 2010s, I believe, and it wasn't an old novel at tthat point. I hope I followed all the rules!