I think I'd try some antibiotics before cutting. Your feed store will have antibiotic that can be added to water.It could be a sinus infection, perhaps? Ear infection? Can you get some antibiotics into her drinking water?
@casportpony might be able to recommend an antibiotic that will help your duck.
Just have to love muskovies. They are wonderful!
Markings/colors on ducklings almost never tell you their sex, only in a couple breeds. The only way to tell is by vent-sexing (which should be done by someone experienced since you can injure them if it is not done properly), or simply waiting until it's a little older to voice-sex the little one. I'm glad he/she has caught up to the size of the others, you must be doing a great job raising him! I'm sure he/she would be much happier with a buddy, though. Have you thought of maybe snatching one of the other ducklings to be a friend for this guy? Might be hard at first for the other one since it's used to being with mom, but ducklings always do better with friends.
