Can my spouse continue work on her current H1b visa while her H4 visa and EAD (COS) is in-process?

[Vijay Singh]

My spouse is working fulltime on H1b visa from last 2 years but now is planning to change the job. We are thinking to convert H1b visa to H4 visa and H4 EAD as my dependent (I am on H1b visa as well). Can she continue working on H1b in her current job or change the job after h1b transfer while her COS to H4 Visa and H4 EAD application is in process. I already have my I-140 approved from my previous job and new I-140 is filed from my current employer.

Can we apply for H4 COS and H4 EAD together? 
Will they both get approved together? 
Does she have to take a break or stop working at any step of the COS process?
Will there be any difficulty in converting back to H1b after she starts working on H4 EAD?
Could the ongoing process to revoke H4 EAD within USCIS result in her application denial?

[gopalakrishnach]

These are just my opinion not legal advice

Can she continue working on H1b in her current job - Yes
change the job after h1b transfer while her COS to H4 Visa and H4 EAD application is in process  - To work on H4 EAD she must get it approved.
Can we apply for H4 COS and H4 EAD together? - Yes
Will they both get approved together? - may be
Does she have to take a break or stop working at any step of the COS process? - she cannot work on H4. She must work on H4 EAD approval not just recepit of H4 EAD.
Will there be any difficulty in converting back to H1b after she starts working on H4 EAD? - risk is always associated. No one can guarantee but it is possible to get back to H1B.
Could the ongoing process to revoke H4 EAD within USCIS result in her application denial? No. Now also you can apply and get H4 EAD approved.