Approved I-140 But Expired H1/H4, Extension inProcess.

[ANarayan]

Hi, I am On H1B Visa and my spouse on H4 Visa (I have completed 4 years in USA). My I-140 got approved but my H1 & Spouse H4 is expired and already applied for extension a month ago in normal processing (Not Premium). As per current pace the H1/H4 extension taking 6 months to approve with Vermont center in normal processing, My H1/H4 extension applied 1 month ago which remains 5 more months approx for approval. In this case can i apply for my spouse H4-EAD now which has approx 3 months processing time? If do so what will be outcome and what will be the expiration time/validity of the H4EAD. Please help me resolve this confusion.