H1 status after returning on H4

Hi
My wife got H1B with COS approved on october 1st 2014 and she has a valid H4 visa till 2017 ( not revoked yet)
Currently she is working for a consultancy.

We are planning to go India in Feb , and we are thinking of getting stamped in India on H4 visa and will return back to US with H4 stamping.

I have two questions here.

  1. what will happen to her H1 status if she enters on H4 .

  2. if she did not resign in the current company and she entered back on H4 , does it create any problem with her employer. we are planning to inform after arriving US.

Thanks