T.O.
Clyde's Willow Creek!
http://www.clydes.com/main/RestaurantsDetail.cfm?Restaura...
It's perfect. There's an outdoor garden next to a fountain; there is a small private space inside. they have many different rooms where they could set you up.
Also, Aylesbury Tea Room in Historic Leesburg. They have a private upstairs room. http://www.aylesburytearoom.com/