In european countries it isnt illegal to have children before marriage. (in fact it is quite common) In china it isnt either, but it is almost non-exsistent due to cultural reasons. So I doubt they have kids, and I doubt they will until ZN retires.
That's because LazyBuddy said: "I think they've been "certified" (completed all the registration and certification process) about 3 yrs ago, however, the wedding is always delayed due to schedule conflict." So that means they are a married couple for a while.
Then it will be rather soon.... Shes already 29 and losing stamina... at most another olympic 4 years later and shes 33 and going to retire... not many athlete goes over 30 for national events