Regarding my wife's current H1B and move to H4

[Abhishek Gupta]

My wife is currently on H1B Visa and is on deputation here in Alpharetta, GA from our Parent company in India.
 

They are currently undergoing downsizing and are planning to send her back by end of November to India. Her H1B is valid till Sep' 2018.
 

My question is that if we file her H4 and EAD together asap ( I have I-140 approved and concurrent H1-B approved ), is she eligible to stay in USA after Nov' 2018 with the basic understanding that the parent company would then fire her here since she does not want to go back.
 

Also if she is fired, there is a 60day rule which can be availed to get a new sponsor/new employer; would she be eligible in accordance to that rule and if she is and she gets a new sponsor/job on her H1-B and concurrently her H4-EAd gets approved, what would happen to her H1B??