EAD - Advanced Parole

[AP]

I received my green card 3 month ago and although both mine and my wife's applications filed on a same day still she is waiting to receive her green card.

 

However she received her "Employment Authorization Card" which is valid through 10/01/2016 and in the bottom of the card it's mentioned:

SERVICE AS I-512 ADVANCED PAROLE

 

She wants to go abroad on March for one month to visit her family. So my question is:

 

Is it fine for her to go out of US? Does that card means she has permission to come back to US? Is there be any possible issue for coming back to US?

 

I really appreciate any response to this question as we are really stressing out.

 

Thanks