H1B transfer in case of authorization on hold

Could you please provide your input for my following doubt.

My Wife came to US on H4 visa in June 2014. Consultancy A applied H1B visa for her. H1B Petition is approved . Since H1B was applied without change of status ( H4 to H1), consultancy company is asking her to go to India for stamping of H1B.

Question : If she get authorization on Hold during stamping in India , can she travel to US on H4 visa when administrative process is in progress?
If Yes, is it possible to change employer ( Employer B) in US who is ready to transfer H1B with Change of status ( H4 to H1B)?

Please provide your comment.