Naw...
My Muscovy's managed to hatch out 2 ducklings out of 12 eggs and 9 live ducklings, and the ducklings are just learning to swim, although they start to panic if the mums walked away, so I put in ramps leading in and out of the water so they wouldn't get stuck.
If she wont accept her duckling there is really nothing you can do.
If you handled the egg/duckling then the egg/duckling wouldn't smell like her, so try rubbing the duckling against her other eggs/ducklings so s/he can pick up the smell. If this doesn't work then you'll have ot raise it.
But...