My wife plans on traveling back to the US on January 3rd and her green card is set to expire on March 8th. I will file the i-751 on December 8th since it's within the 90 day window.
My concern is that she may not have the i-751 receipt by that time and although her green card won't be expired by the time she re-enters, is she expected to have any reentry issues since its close to expiration?