Re-File 2018 as Joint/Married?

In 2018 me and my wife got married. She had filed taxes for that year as single and I have yet to file that years taxes (working on it now). Subsequently, she received a big bill for this apparent error and we need to re-file as married to correct the situation apparently.

 

I'm wondering what the correct way to go about this is? I bought the Turbotax 2018 Home & Business software and have done my self-employed businesses portion so far. (this is what I've used in years prior)

 

When it gets to the Personal tab I'm assuming I will just enter her W-2 income info etc as the software asks for it and we will just send in this new (joint) tax return and that will essentially "correct" the previous return that was erroneously filed as single?

 

Is there anything else that needs to be done to fix this situation correctly?

 

Thank you for any advice!