Abandoned Green Card and Re-Entry

[Bee]

Our situation is as follows, we need some help so we know what our options are:
I am a US citizen, my wife is from Europe. She got a Greencard December 2008. We did not intend to live or return to the US, but applied for the GC because she overstayed her visa and did not want to get a 10 year bar.
We left the US July 2009 (19 months) and have not been back since. We do not have an exit stamp in our passports, just an entry stamp to Central America.

Personal reasons force us to inquire:
Is it possible to re-enter the US as a visitor?
Will her GC be taken by the authorities?
Should she surrender her GC to the local embassy of US?
Should she apply for a re-entry permit from overseas?
Can the GC be retained or does she have to apply from scratch again?

Thanks for the help in advance.

[immihelp]

She has already lost her green card status.

If she wants to visit the U.S., she should apply for visitors visa.

If she wants to live in the U.S., she should apply for green card.