Stamped H1B to H4 and back to H1B COS

[somasundar]

Hi,

I have a H1B visa valid till Sep-2019. My Fiancee has H1B visa stamped valid till end of next year. She has never been in US before on H1. She couldn't able to make it to US through her current employer. Once we are married I'm planning to get her to US to start working here. I have few doubts regarding this.

1. If she go for H-4 stamping now , will her H1B gets cancelled?

2. If she travel to US using H4 , can she change visa status to H1B for another employer?

3. If yes, what is the process or steps for that? 

Let me know whether there is a better alternative solution for this.

Thanks in advance.