Thank you, @Anonymous_ .
Re: Is there an executor of the estate?
Yes, the surviving spouse (their Mom) is the executor of the estate. But that may not be relevant since it seems the Inherited IRAs would go to the grandchildren next because of the "To my descendants who survive me, per stirpes." beneficiary designation.
They would be fine (seems preferred) if it went to their Mom, but it doesn't seem that's how the beneficiary designation functions.
