Thank you, Vanessa.
I did what you recommended, and it worked like a charm. The return has been e-filed, and all's right with (that tiny piece of) the world.
A final return will have to be filed for 2022, as she had received her Social Security and pension checks for January 2022 prior to the report of her death reaching SSA and other pension source. But that won't be a problem for me.
