I have an H1B petition valid till 2020 shown on form I-797B and same goes for my I-94 and my passport. My spouse is under H4 status as a dependent. Her old passport had expiry date in November 2018, and same was true for her I-94. So she traveled to her home country, renewed the passport and came back to US with both passports in August 2018. Now I check in CBP and see that her I-94 "admit until date" shows 2020. Could be of minor importance, but that same page shows her old passport number (can't find her in CBP with the new passport number).
Does she still need to file form I-539 to extend her H4 status before November 2018 (which is old passport's expiry date)? Or has the H4 status been extended by default since I-94 has been extended? I'm probably confused with terminology here, but any advice will be appreciated. I'm not from India, if that's required to mention.