RMD is required for all retirement accounts. That is why Turbo Tax has to ask the question. When you inherit an account from someone other than your spouse, you have to take an RMD based on that person's age.
If you took a total distribution, the RMD requirement is met.
If you are taking monthly payments, the RMD requirement is met if the payments are based on your mother's age.
The Required Minimum Distribution (RMD) amount for a retirement account is determined by applying a life expectancy factor set by the IRS to your account balance at the end of the previous year. To calculate your RMD:
Find your age in the IRS Uniform Lifetime Table (below).
Locate the corresponding life expectancy factor.
Divide your retirement account balance as of December 31 of the prior year by your life expectancy factor.
The IRS has worksheets for you to do these calculations. See
https://www.irs.gov/Retirement-Plans/Plan-Participant,-Employee/Required-Minimum-Distribution-Worksh...
