T-IRA owner died pre-secure Act 1.0 & after his RBD for RMDs
Beneficiary, the son, has been stretching payouts for years. Son died this year. His wife is the benefciairy

Question
Whose life expectancy does the surviving spouse as successor beneficiary use? Hers? Or does she continue where the original beneficiary left off?

I believe the wife as SB is now subject 10 year payout. Confirmation needed

Thank you