My daughter has the same problem. She used an English name in New Zealand. When we applied for New Zealand citizens, that name became her first name and her Chinese given name became middle. We learnt from the Dept. of Internal Affairs that we should fill a form at that time, but we just do not remember. Now we hope the people there are able to find that form. By the way, I talked to my attorney about this issue; he said it should be OK if I just write something to explain how she changed her name. I am not sure for that.