Age 70 1/2 required minimum distribution calculations for a participant have been done based on his and his spouse’s ages, recalculating. The participant recently died and it has now been discovered that the spouse signed off for the daughter to be the beneficiary. How should distributions be calculated at this point?

It depends. What do you mean that spouse "signed-off"? What form is the benefit being paid in? What is the normal form? Is this a DB or a DC plan?