Adorable! Trust me - any mom is better than no mom! The babies may end up confused about a few things, but I think it's much better than an incubator (although we have an incubator as back-up - I try to get the results "foster parents" as young as possible.)
That said, I generally use my Muscovy moms to hatch out mallard derived ducks and goslings. They don't exactly speak the same language, but at least they're closer than turkey! Miss Shadow just hatched a cute little gosling (number two didn't make it) and several moms hatched out a combo of 11 Khaki Campbell ducklings of which unfortunately, 9 are drakes. Miss Custard is about to get 10 Khaki eggs tomorrow morning and I'm really hoping she can improve that ratio!