Retirement tax questions

This is a follow-up question to the above, but with more specifics...

When my wife's mother passed away in Dec 2018, a check for final SSI was sent to my wife (serving as estate administrator) and paid out in Jan. 2019. We later received an SSA-1099 for TY19.  On the SSA-1099, Box 1 lists my wife's name even though guidance on the back of the form says "'Name' - shows the name of the person for whom we paid benefits."  Furthermore, Box 7 lists "[Wife's Name] On Acct of [Mother's Name] Dec'd".  

 

The money received was part of her deceased mother's estate. As such, I don't believe it's part of our (MFJ) income.  Is that an accurate assessment?