今天收到移民局的邮件，下面的这些话实在不明白，请大家不吝赐教。
The above petition has been approved. The petition indicates that the person for whom you are petitioning is in the United States and will apply for adjustment of status. The evidence indicates that he or she is not eligible to file an adjustment of status application. This determination is based on the information submitted with the petition and any relating files. If the person for whom you are petitioning believes that he or she is eligible adjustment of status, then he or she should contact the local USCIS office for more information.
什么是adjustment of status？我的sister现在是H4，难道要她回中国去等绿卡吗？
谢谢