Green Card status check

[canyonlands]

Hi,
My mother was a green card holder in the US nine years ago.
When she had a bad health problems, she went back to her country.
She then returned her green card there in order to receive health benefit in the country.
Now she wanted to rejoin with me.

Do anyone know a way to check to see if her green card is still active?
If not, what are her choices?

Thanks,

[immihelp]

She has to apply all over again. You can sponsor if you are US citizen.