I was married on 8/28/18. trying to file taxes and I don't have agi for her. how can I efile without it

[DoninGA]

To e-file a tax return you need the 2017 AGI for each of you when filing a joint tax return.  If your spouse did not file a 2017 tax return then enter a 0 for their 2017 AGI.  If the IRS continues to reject your tax return for the 2017 AGI then you will have to print and mail the tax return.

See this TurboTax support FAQ for printing a tax return for mailing when using the online editions - https://ttlc.intuit.com/questions/1944348-how-do-i-print-and-mail-my-return-in-turbotax-online