-No. If she wants to go back to China, she may not need to file change of status (I-539) in US, and just bring the I-20 to a US Consulate in China to apply for the F1 visa to come back.
因為B2還有效,不知是否能在等待期間回國,批了之後再以B2回美國上學?
-No. If she uses the B2 visa to reenter US, her status will be B2 again, not F1, thus, she can not study.