She was in the Christmas commercial, yes.
Carol of the Bells
The nutcracker song.
Christmas Wrapping by the Waitreses
The 2011 Christmas commercial that Time Warner is airing contains a song by Guster, "Tiny Tree Christmas ♫ ... and then appears a perfect Christmas time"
Tiny tree Christmas
This is clearly a song created by Kmart for it's 2011 Christmas Ads. It is simply a jingle, not a song.
lose yourself
Raveonettes
Pomplamoose
Stevie Wonder - What Christmas Means To Me
The music on the Dobbies Christmas commercial is "The Christmas Song" by The Raveonettes, from the album "Music from the O.C. (Mix 3)".