H4 to H1B and Back to H4 pending

[barkulkum]

My Wife H1B visa has been approved on Oct 18 2011 and she joined her employer for work from January 1st 2012 after undergoing training for two months and was working for them for about 1 month and since the daycare really does not work for our 4 month old daughter she had to resign her job from Feb 24th, 2012 so she was in her employer payroll from Jan 1st to 2012 to Feb 1st 2012 and she got paid on Feb 16th 2012. From February 1st to February 24th 2012 she was on vacation.

We immediately applied for her H1B to H4 change of status through an immigration attorney and we have got the receipt # dated Feb 27th 2012. My Questions are

a. Now while we are waiting for her approval of I539 COS application our question is can she travel to home country and what will happen to her I539 application.

b. Her visa stamping on her passport has been expired and we wanted to attend visa interview in our Home Country for my H1B and her H4 as a dependent. Will there be any problem doing this?

c. Is she out of status from Oct 18 2011 to Dec 31 2011 and will it create problem in our future green card process.

I sincerely appreciate the help. Please advise