Thank you for the response and the links to additional information. Based on what I read under the TT Link for Seniors Filing, it appears she does not need to file. I came to this conclusion based on her TOTAL income being $21k, but $15.5K of that is her SS income. Since you do not include SS income in the AGI calculation, her actual AGI is only $5.5K, which is well below the $14,050 AGI limit for determining when a Senior, over 65, would need to file or not. Does this sound correct?
