Separate them where they can still see each other because you'll have to do it once you get her a mate anyway if you want pure goslings one day. Separating will keep her safe from the Chinese, stress from bullying is not good for their health.
That's why they are bullying her she is an intruder to them. Integration always has to be slow and with fencing in between those that are resident and the new ones. Once they all have lived side by side for a while then you slowly introduce with supervision a little while during the day until they can all be together with out any one being bullied.
Your going to have to be ready to brood these goslings if you can't keep it warm when they hatch check your temps in your shed where she is brooding and if you can keep it around 40* or above and keep them inside for a couple weeks you may not have much trouble but you'll have to make sure she is keeping the gosling warm and caring for them. Sometimes new mamas need our help, and you don't want them taking goslings out in frigid temps or when it's snowing or raining they can chill really fast. You also need to make sure your brooding goose is getting adequate food and water it takes alot out of them when brooding and in winter even more so.
