H4 and H4 EAD Extension

[balakrishna sangi]

Hi 

My wife H4 and H4 EAD was expired in Sep 30 2018 and I already applied for my wife"s extension in Sep 2018 before it is expiring  with my  current H1B (I797) expiring in  april 01 2019. so far no approval yet it is still processing.

Now I am applying for my H1b extension with premium processing, so my lawyer want me to apply again my wife's H4 and H4 ead with my premium processing. 

as per my lawyer my wife H4 will get approval only until my current H1b expiring date and need to apply again my wife's H4.  

I do not understand because my wife's H4 and H4 ead are already in the process when they are approving my wifes H4 do they look online about my h1b (I-797) expiring date and approved

or they just look in to my paper work submitted with H4 and H4 ead and approve with my wife's h4 & h4ead until April 01 2019 even though my h1b extension  will get approved before thru premium processing for next 3 years until 2022.

please let me know if I have to apply again my h4 and h4 ead with my premium processing with H4 and H4 ead  application  already in pending (which was applied earlier in sep 2018)  (or) wait for the h4 and h4 ead to get approved (which was applied earlier in sep 2018). 

thank you