I used patterns for both robes:
Simplicity 5931 for the big girl (I keep promising the hubs a robe too. Someday.)
Simplicity Crafts 5276 for the doll
Both patterns were pretty simple, except for the collar. It did take me a few minutes to figure out what they were talking about there.
I love the idea of matching doll/kid things. Miss A LOVES the doll stuff I make her. So far she's completely uninterested in wearing anything I make for her....except her Tinkerbell Dress. Pics on that forthcoming.