H4-EAD to H1B COS With extension

[ATLURIBH]

My Wife is currently on H4 EAD status that expires in May'2020. 
she has approved I140 and her H1B extension based on I140 is currently pending with USCIS.
what happens to her status post May'2020 if H1B approval is not obtained by then.
Can she stay in US without working based on pending H1B petition or should i file for her H4 extension post May along with my H1B extension.
What are her options to maintain legal status in US(I understand she cannot work).
 

[User099]

Its better to submit a H4 extension just because we don't know how the H1 petition might turn up. H4 will be a fall back if H1 gets rejected. 

But the problem you will run into is if H4 is approved after H1, then she will end up in H4. You might have to withdraw the H4 if its pending and H1 is approved. 

[gopalakrishnach]

I guess she has H1B receipt. If employer/client agrees she can work on that receipt. I may be wrong but I guess she can work only 240 days past I94 or something like that. Please find out.

15 hours ago, User099 said:

Its better to submit a H4 extension just because we don't know how the H1 petition might turn up. H4 will be a fall back if H1 gets rejected. 

But the problem you will run into is if H4 is approved after H1, then she will end up in H4. You might have to withdraw the H4 if its pending and H1 is approved. 

I agree with this. Better to submit H4 and H4 EAD and if H1B approved first immediately withdraw H4 application.