I've seen here vids before mellow, and she's pretty talented. She used to have some cool duet stuff posted with a dude, but they're gone (as I suspect he is too). Ahh the folly of young love. Such is the way -- Cher sans Sonny, Tina sans Ike, and so on.
She sings in a style that's very common nowadays with so many indie rock and folk minstrels. Reminds me of one of my faves, Jolie Holland.
Edit: I watched the My Favorite Things vid, and you can forget my hasty comment above. Pomplamoose is the project I saw before. Their myspace page shows they're still active, and perhaps it's not a romantic involvement. Great playful music from both as well as the solo stuff.