Will my wife get a 1095-A form ? She is on Medicare and then has a supplement with Blue Cross Blue Sheild?

No, your wife will not get a Form 1095-A. You only get a 1095-A for insurance from the Marketplace ("Obamacare"), not for Medicare or a Medicare supplemental policy.

You only get a 1095A if you have had health insurance from the marketplace---also called "Obamacare", from healthcare.gov    If she only had Medicare and no insurance from the marketplace she will not get a 1095A.   When it asks you just say NO and keep going.