Required to go India

My h1b and wife’s h4 has expired last month and employer has applied for an extension request in non premium mode.
My mother in law who is in India is in serious stage with a severe health condition. I am looking my option to send atleast my wife to India to see her mother.
What are her options to come back to US if the visa extension request gets approved? (Planning to request my employer to change the application to premium mode)
Does the US embassy in India provide Dropbox now for h4?
Please guide us.

If she travels outside the US while her extension of status application is pending, USCIS may denied treating the application as abandoned. The only option is to go for visa stamping if her visa will not be valid at the time she travels back.

Thanks Kalpesh for the response.
So does that mean the best option available for her if she wants to return to US is to get H4 extension approved and then travel to India?
If that is the case, will US embassy in India do the stamping?