at the beginning, and for the first two verses, she's picking the notes 
D , D , C# , C# , B , B , A
you can also play the chords D, D, Bm , D for the verses.

then for the ohhhhs, she's playing a G chord.

then the chord progression for the chorus is 
Bm , G , D , A
Bm , G , D , A
Bm , Bm , G , D
G , A

then for the bridge the chords are 
G , G , D , A ,  G , G , A , A


This is my first tab.  I couldn't find the chords to this song, so I decided to 
try and figure them out.  They may not be exactly right.