H4 Extension while having separate H1B that will start shortly


I am in H1B and my wife is in H4. She got her new H1B visa in April which will be active in October. I need to file my H1 extension in September. Should I file for her H4 extension as well (once mine is approved). What if her H1 has not started when I approve for her H4 extension OR what if it has already started…please let me know both the cases. I am not sure which status holds good…H1B or H4 (if H4 extension is approved as the latest)?