She did not go back China after she was a H4 holder. The only possible status gap for her is what I mentioned in my question.
I just found out the original petition forms for applying my H1 and her H4. Both my I-129 and her I-539 show that the "current status" expires on 10/12/2005 (this means there is no status gap for her). I'll try if I can find out the original whole petition package so that I can figure out why her I-539 petition also showed the expiration date of "current status" is 10/12/2005 (after several times move and computer system failure, it is not easy to do so right now).
As for why my H1 starting date is different with my wife's H4, I have no idea.
Thank you very much!
