“Yes she can. Once she does, she goes out of H4 status”
---------And if she has valid H4 visa stamp in her passport she can again be on H4 if she wishes she has to exit US and enter on H4 visa she will get newI-94 as H4, but if the primary applicant uses EAD then spouse is no more on H4, if spouse uses EAD no affect on your H1 status