After looking around the net for awhile, it seems she was likely a Black Swede, probably mixed with Mallard (as she was not large, weighing only 2..3 pounds at most- yet she was very-well fed). ;)
We lost our "Squeaky"-duck to a predator in early January. She was a feral escape that walked cross-country onto our place one afternoon. Initially very skittish, but we became close friends and she loved to race me and our kayak around the pond.
She was small-to-medium in size, and not heavy...