No you do not use your mother's AGI. If you filed a 2019 tax return--even if you were claimed as a dependent---you have an AGI on line 8b of your 2019 return.
When you entered your own information in My Info did you answer NO to the question about whether you can be claimed as someone else's dependent?
If filing with zero is rejected then file again but select the option that you did not file last year. The IRS does not see that question and it will allow you to e-file with no AGI question.
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
