Can my wife have both H1b and H4 stamping in same visit to india

[Hary singh]

An employer filed H1b for my Wife on 01-April-2016 , then she came to USA on H4 visa on 05-June-2016 , Her H1b petition got approved in Jan-2017 without change of status so she was still on H4 status in USA , Her H4 was getting expired on Aug-2017 so I filled her (H4 extension + H4 EAD based on my I-140) in Fab-2017 and both H4 extension and EAD got approved in March 2017 , she started working on H4 EAD and she is still working on H4 EAD in USA , next month in Oct-2017 we both are going to India. My H1b and my wife's H4 extension will be eligible for drop box facility. 
Since my wife has valid petition for both H4 extension and her H1b. She want to continue working with her current employer on H4 EAD. So my questions are:
1. Can she skip H1b visa stamping this time during our visit to India and just go for H4 stamping and re-enter US on H4 visa so that she can resume her job on H4 EAD?
2. Can she go for both H1b visa stamping and H4 visa stamping ? and enter USA on H4 visa and later apply for COS to H1b once she want to work on H1b?
3. If she does not go for H1b stamping and go for H4 stamping , will her H1b be cancelled? 
4. Can she utilize the benefit of both H1b and H4 EAD one after the other ?

[shekar11#]

On 10/1/2017 at 6:02 AM, Hary singh said:

An employer filed H1b for my Wife on 01-April-2016 , then she came to USA on H4 visa on 05-June-2016 , Her H1b petition got approved in Jan-2017 without change of status so she was still on H4 status in USA , Her H4 was getting expired on Aug-2017 so I filled her (H4 extension + H4 EAD based on my I-140) in Fab-2017 and both H4 extension and EAD got approved in March 2017 , she started working on H4 EAD and she is still working on H4 EAD in USA , next month in Oct-2017 we both are going to India. My H1b and my wife's H4 extension will be eligible for drop box facility. 
Since my wife has valid petition for both H4 extension and her H1b. She want to continue working with her current employer on H4 EAD. So my questions are:
1. Can she skip H1b visa stamping this time during our visit to India and just go for H4 stamping and re-enter US on H4 visa so that she can resume her job on H4 EAD?
2. Can she go for both H1b visa stamping and H4 visa stamping ? and enter USA on H4 visa and later apply for COS to H1b once she want to work on H1b?
3. If she does not go for H1b stamping and go for H4 stamping , will her H1b be cancelled? 
4. Can she utilize the benefit of both H1b and H4 EAD one after the other ?

1. Yes.

2. She can but sometimes visa officer can cancel the existing visa while issuing new visa.

3. nope.

4. Yes. But she has to file COS after she enters.