I don't know much about Lana Del ray, but from what I have heard I like.
As for her being authentic, it looks like she has paid her dues, so to speak, in the club scene. So that's something, for me. other than that I couldn't say.
Another band you should check out, Best Coast. To me they are what California sounds like. The lyrics and music are well, sloppy, but it works.
The album
Crazy for You is the best. I haven't really listened to much off the new one,
The Only Place. Frankly, I just can't get into it. But add them to the list