Nadège is the French equivalent of
Nadezhda (meaning hope), a girl in my students' hall of residence was called that name. Well, that was in
Brittany, so it might be a Breton name (but actually, I don't think so).
I agree, French names make great middle names. It's just that some might be a little complicated to pronounce. I don't know, is Nadège easy or at least ok to pronounce?
(I like the meaning "stern hope" ;-) )