When did she file 2019? The IRS was late Processing 2019 so the AGI didn't get entered. Try using 0 (zero) for the AGI. Or try to get it from the IRS.
You need your 2019 AGI to efile 2020. The AGI is on 2019 1040 line 8b. If you filed a Joint return you use the same AGI for each spouse.
How to find the AGI.
https://ttlc.intuit.com/community/agi/help/how-do-i-find-last-year-s-agi/01/25947
Or request a transcript from the IRS
https://www.irs.gov/individuals/get-transcript
