Xiaobaitu, Please help!!!!

My mother visited on 8/2002. I extended her B1 visa for another half a year on 12/2002. The case has been approved. Unfortunately, I didn't receive the approval letter. But now I still can find out her approved case online. Now my mother wants to visit me again. In such case, could I print out the approved page online, combining with the receipt notice, for her visa application? Or I should fill in the form I824 for a duplicate approval notice.

Also, do you think my mother's visa application could be refused due to her visa extension here?

Thanks a lot!!!!