She needs H1 visa.

The H1 I-797 she got does not have an I-94 (even if does have I-94, that I-94 became invalid when she left North America, the re-enter I-94 using B visa will be in B1 or B2), she needs to enter USA with H1 visa to start her H1 status (get a new I-94 in H1B).