If (all met)
1) she applied H-4 EOS before leaving
2) she entered using H-4 visa
3) her EOS was approved after her entry
she does not need to do anything, as the I-94 on her H-4 approval notice grants her status through its expiration.
http://blog.wenxuecity.com/blogview.php?date=200709&postID=16851#EosCos
If she wants travel, http://blog.wenxuecity.com/blogview.php?date=200710&postID=30824