What should be my next step?

My girlfriend is an immigrant ,we've been dating for a year and a half. And plan on getting married in June,I'm not getting married for any reason other than love. The problem I'm having is ,her workers permit expired last March so I was wondering do we need to get her permit renewed before we can get married or if we get married,does that grant her the right to be in the US? I'm trying to go in the right direction so any advice would help. I don't want her to get deported ,I don't wanna loose her .she's been here since she was 2, and last year was the first year her permit expired Cuz in all honesty we weren't financially stable to apply.