what is the name of this female singer?

i'm totally blanking out here, but i'm trying to remember the name of a female singer. she has a raspy voice, long dark hair, brown eyes. she dresses boho style and has big cheek bones. she's won a ton of grammy's. she was more popular in early 2000. i think her name either starts with C or J. she has a video on the beach. it's a very romantic song. and she almost always plays acoustic guitar by the way.