The client had/has the right to the money. It isn't ignored. It doesn't help to state it in a way that is misleading.

She can get the money from the issuer. They would be holding the amount as Uncashed; or, they turned it over to the State. Ignoring the checks didn't change reality.

Proving you don't need RMD means contacting the entity and dealing with life.

It was not rolled over. She will be able to get the money, and use that money to pay the taxes.

This needs to be addressed. If it is supposed to be rolled, then direct transfer and get it over with.