H1 & H4 EAD Transfer Question

[maheshnalla]

Hello Everyone,

I'm with employer A and my current H1 is valid until Oct - 2017. I got my I-140 approved in April 2016, and subsequently applied for my wife H4 Ead and she got approval until Oct -2017. She didn't started working yet, but about to start looking for opportunities.

Now I got an offer from a new Company B, and willing to transfer my H1 to new company B. 

My question is whether my wife can work on H4 Ead which is from my previous Company A, or do i need to apply for h4 extension and h4 ead concurrently with my H1b Transfer.

Please let me know, any input would be helpful. 

Thanks