Welcome to BYC!
Depends on what her laying issues are and what you guys did.. Did she get a hormone implant to stop her from laying? Egg laying is dependent upon many things including age, nutrition, genetics, daylight, etc.
There aren't enough details for us to give a great response.. but one thing I would definitely recommend is that you write your questions down and then call the office staff and either see about speaking with the vet or getting a message relayed and replied to. I wouldn't presume the vets inexperience or ignorance due to the lack of elaboration on that single statement.
Muscovy (since they are mentioned several times) are water fowl more closely related to geese according to research but they aren't technically ducks for anyone who didn't know that.
Do you know what breed you duck is and what her age is? Also what is your general location? Consider adding it to your profile as it may help folks make their best suggestion possible regarding which resources may be available, disease information, and more.
Hope your duck is thriving and well!