Dwarf Pekin duck?

[Soon2BChixMom]

So, she is by herself now? Have you raised ducks before? If she is by herself, she needs a duck friend to keep company with. Your other ducklings may have gotten into something toxic. Really no way of knowing what they died from without doing a necropsy.
Maybe she's eating too many treats and not getting enough nutrition.
Tons of fresh vegetables could be hindering her getting adequate nutrition from her feed. She is a domestic duck and as such won't forage enough like a wild duck would. Cut back on the veggies and any other treats see if that helps with her weight and general appearance.

 

[chickens really]

Hello being she is 3 or so months old she is possibly going through a juvenile molt. Feathers get ratty looking. Don't feed her layer pellets. A finisher feed would be better.
She is at an awkward age and it depends on the breeding stock if she will be any bigger.

 

[Christina serviss]

Hi I have a 6 week old pekin that was purchased from tractor supply around easter with 5 others and she or he is still the same size .I think it may have dwarfism. How do I keep it warm? Healthy, will it get feathers. Will it grow. It's so tiny it's still just little yellow fuz

 

[JacinLarkwell]

Have y'all considered that they might be a different white duck breed?

 

[CoriM]

Maybe she's a white layer - they look like pekins but are much smaller. If she is alone now you really need to find a partner for her. She will be too miserable - ducks need a group. Hopefully you've also figured out a way to keep her safe from predators so you don't lose her!