Chinese missions in this country generally will recognize your own statement if the statement has your (US)local athority's confirmation. For example, you can make any kind of statement and get it public notarized, and then send it to your local state's secretary of state's office with a fee to get SOS' confirmation, and then send the whole thing to the local chinese mission(embassy or consulate general), they will provide their proof based on this. such proof may be admissable back in China. I know you can prove your marriage status that way. Please call LA consulate and see if they'll accept that.