H4 to H1B COS

[rahuljosh0072000]

Will need your advice for below matter.

My wife petition was picked up in h1B lottery in the year 2016 and her H1B I-797 petition was approved in March 2017 for 3 years but due to trump era, and other reason her employer i.e. consulting firm have yet not done visa stamping.

 Now she has traveled to the USA on H4 visa in August, so have below queries: -

1- Is it possible to transfer to another employer just based on I-797 approval copy?

2-Is it necessary to stick with the same employer until they initiate her h1B visa stamping and then only she can transfer her visa to another employer?

3-Is there any other work around to Change her visa status to h1B visa.