Topic: Wife on H1b, F2A PD is Oct 13, 2015 - Maternity Leave

I am a permanent resident (since 2012 February) My wife is a h1b visa holder and we got married in April 2015. We filed I-130 for her in F2A Category and our priority date is October 13, 2015 We have been following the visa bulletin to find out when we can take the next step In the last two visa bulletins our date is current per Chart B i.e. we can file I-485 since our date is prior to Oct 15, 2015. But the USCIS visa bulletin is asking us to follow Chart A which has Nov 2014 current date. To complicate the issue my wife is pregnant with a due date of Jan 2017. It seems like H1b holders are allowed only 6 weeks of maternity leave but we dont think she will be able to start work 7 weeks after delivery. Is there anyway she can keep her legal status even if he doesnt rejoin her work? Although it is unlikely that our PD becomes current, if it does before end of the year, how long does it take for the EAD card to arrive after filing I-485? I will apply for citizenship this November but I dont expect to get my citizenship until March 2017 (at the earliest) and we can only apply for expediting her GC application at that point. is there anyway for her to be legally present in US while she waits for her EAD card or GC if she decides to take a longer maternity leave than 6 weeks?