I'll do my best to describe it.
It's black, sleeveless, with a crew neckline, like this
. It falls slightly above the knee and has a full skirt, like this
, but not as short. The skirt has a layer of chiffon over it, with a black chiffon sash attached, that can be tied in the front or back. I can't remember who makes it but I know I got it at Loehmann's.
I've got almost 3" on you, so it would be longer on you.