Green card before entering the U.S

[jcadima]

My mother recently got her IR-5 visa approved , she lives outside of the U.S, i was the petitioner and paid the immigrant visa fee 2 weeks after her visa was mailed to her.
I plan on going to my home country and bring her with me, USCIS status message says that her green card will be mailed before i plan to bring her( about one month before ),
the question i have is:

since her green card is going to arrive before she comes to the U.S and i will receive it and take it with me when i bring her to the U.S,
i see that U.S citizens and Green card holders are able to scan their passports and green card cards at immigration checkpoints, my question is the following:
- is she going to need to scan her green card in one of those checkpoints even though its the first time she's in the U.S ?
or will she need to go first to the immigration line and present the sealed package first and her green card and not scan her green card at one of those checkpoints ?

- OR does she need to do both: scan her green card and go to the immigration line ?

[daggit]

She will not receive her green card until after she arrives in the US. The only way for her to enter the US is through the valid IR-5 visa. She presents the sealed package and becomes a permanent resident the moment her visa is stamped at the airport, while physically present in the US; not while living abroad.