Mallard Hybrid Hen in New Jersey

I'm not the greatest at identifying hybrids- I've blogged about them twice before with mixed results (one was likely some kind of domestic duck hybrid, and the other was a Green-winged Teal, which was actually a rarity for the time of year I saw it)- BUT I'll give it a shot anyway. I'd love to know everyone's thoughts!
 
I was in Beach Haven, NJ this past June for a friend's wedding. As part of the festivities we went to the rehearsal dinner, which was hosted by another one of their friends with a canal-front home. There were two different families of mallard ducks swimming close to the dock- looking for a free meal. I noticed that one of the female mallards (or "hens") had an unusual amount of white on her neck and wing. Does anyone have any idea what type of mallard hybrid this might be?

Mallard Hybrid: