回复：谢谢回答，我到网上查她的I-94到期是五月份，不是护照上的六月份，是不是系统里还是6个月的时间？

It seems there might be a mistake note in her passport. Normally the I-94 expiration date is the last date for her to stay in US. If she wants to stay until June, she had better go to the local CBP Deferred Office to check it in case she overstays. She may file a B2 extension before the I-94 expires if she wants to stay in US for longer time.