How to Revive GC surrendered 2 yrs back?

My Wife held GC statys for 4 yrs but later it in 2010 due to family and health requirement as she could not travel to US to keep GC live,2 months later she travelled to US for work on L1 till Sept 2010 and in apr 2011 she again travelled on L1.Now we plan to be permanent in US and trying to revive my wife’s GC.Is there a way?