See her folks, they are about to be your folks too anyway.
You should have asked this question when you're having a relationship with her, if you think that to suddenly pop up on her parents with the message that you two are about get married might be unnerving, just think that, they would be more disturbed to find out that the two of you are already in a relationship for awhile.
I guess that the only advice one can give is to treat your girlfriend's parents like your own. After all, when you married someone, in a kind of way you also married her family. I think that the answer is clear, see her folks and talk to them.
You should have asked this question when you're having a relationship with her, if you think that to suddenly pop up on her parents with the message that you two are about get married might be unnerving, just think that, they would be more disturbed to find out that the two of you are already in a relationship for awhile.
I guess that the only advice one can give is to treat your girlfriend's parents like your own. After all, when you married someone, in a kind of way you also married her family. I think that the answer is clear, see her folks and talk to them.