Mom died in Feb 2019 & I'm doing her 2018 taxes. The question asked online is did I inherit the IRA. I did, but not until last week (March 2019). Should I answer no?

Yes she was alive on 12/31/18.  And it is not if you inherited the IRA.  You are doing her return.  So did she inherit the IRA from someone else?

She didn't inherit it.  I inherited her IRA, but only just last week.    Thanks for clarifying for me!  I was confused because early on it asked if I was filing for someone who was deceased and I responded yes.

Next year when you do your return you will get a 1099R for it for yourself.  Then you say you did inherit it.  If she was over 70 1/2 you need to keep taking the RMD out of it.  Ask the plan or bank about it.  Maybe @dmertz can give you more info on inherited IRA.

Her IRA was distributed to me & my brother last week.  We opted to have it 'inherited' and then immediately closed it and will pay taxes on the money next year.  She didn't have much in it as she was almost 90 and had been taking mandatory distributions for years.   Thanks again for helping!

And next year when you enter the distribution into TurboTax, just indicate that it was all RMD and was the entire RMD required from this account.