Retirement tax questions

Thank you so very much for your help and condolences. 

I am not sure of the basis but may have paperwork somewhere. I did receive a letter from the teacher’s retirement system about the non taxable contributions that were unrecovered and a precise amount that would have to be entered as a deduction on her last return. The 1099-R was only giving a statement as to the taxable income up until her passing.

 

This is the 2nd return I’ve had to file as she passed before her 2019 taxes were filed. 

Thank you truly for your help and consideration!