WOW! Have you seen any mating? I guess I should ask first, do you have a gander also. I assume you do, since mentioned a pair. My chinese hens collect 6-7 eggs and go broody. They also steal other hens eggs, LOL if they can get away with it. I have seen mating still going on with the embden, but not my chinese. If she is laying, she may very well go broody. If she does, candle at around 7 days, and you will know
Chinese are excellent mothers. She will likely do very well raising them. Normally the hens mature around 8 months.