Grannie better check again or get a better tax accountant.
I live in Illinois, am retired and living well on Soc Sec and good RMD. The fed’s tax 85% of Soc Sec and all of the RMD income. Illinois taxes none of it, as in zero.
When I got out of the Army, many years ago, I discovered hat Illinois also treats veterans very well with tuition assistance at the state schools as well as the private ones. I got a masters degree with state and fed assistance.
Indeed, Governor Porkchop just tried to change the state constitution to allow income taxes at different rates for different classes of taxpayers. It would have allowed the state to start charging retiree income at “a much lower rate” than others. It failed.