You should start a new account instead of trying to use an old account that was used for joint returns in the past. It is too hard to remove all the embedded "spouse" stuff from the old account. Start a new account with a new user ID to file Single.
Do you still have her W-2 on your return?
TurboTax carries over text data from year to year to save you typing, but this does mean that sometimes you have to go find and delete forms that you don't need or want.
Go to Wages & Income and look for the W-2s and see if there one one you should delete.
If you used Turbo Tax last year you should start a brand new account for yourself and not transfer from last year. Online is only good for 1 return. But you can use the same email address for 5 accounts. Start another Online return here. Sign up and start a new account.
https://turbotax.intuit.com/personal-taxes/online
Getting Divorced article
https://turbotax.intuit.com/tax-tips/marriage/getting-divorced/L20NC66cf
Video tips for Divorced couples
https://turbotax.intuit.com/tax-tips/marriage/video-tax-tips-for-divorced-couples/L8YqvF7p5
And see what AGI to use
https://ttlc.intuit.com/community/agi/help/what-agi-should-i-enter-if-i-m-recently-divorced-or-widowed/00/26954