Quote Quoting mmadsen55
My question is how long after the interview will the green card arrive?
"It depends". It may be that she gets a passport stamp which reflects her new status pending the arrival of her Green Card (which, for immigration purposes, is proof of permanent residency and of qualification for a SSN and employment). I've heard stories of it taking as much as a year to receive the actual Green Card.

Quote Quoting mmadsen55
Secondly, will the green card allow her to travel outside the country, and return without any problems?
Once she is a permanent resident, she can travel freely outside of the United States. A reentry permit is needed to reenter the United States after trips greater than one year but less than two years in duration.