H4 Status when H1 is tranfered?

Hi,

Recently I transferred my H1 visa from one employer to another employer.

Before my transfer of H1 initiated(when I am with my previous employer), My wife came to the USA on H4 dependent Visa.After few months, I transferred my H1 and it got approved.Now my Wife is traveling to India.

Will there be any problem for her while returning back to the USA?

Does she need to go for stamping as I changed my employer?

She needs to apply new H4 based on your new H1 and get this stamped in India to enter back to US

Is there any dropbox option for her as the previous h1 is less than 1 year?