No additional documents required. Pretty much the same process as her first entry to U.S. But it could be more helpful if you write a letter to the Immigration office on her behalf, assuming you would like to request for another 6-month stay for your mom.
p*k
6 楼
您指的原来配额还有效是什么意思?是今年2月份Approved. 我手上有I797 approval, 今年3月份去使馆盖了个H1B visa stamp.不过上个月去申请 B1 visa的时候被签证官在我原来的H1Bvisa stamp 上划了个叉。