Can I do both of my parents' tax returns together though my mother died in December 2018?

[trotsky11]

I am unable to complete the tax returns together, as I do for my wife and me.

[TurboTaxKim]

I’m sorry to hear of your loss. You won't be able to prepare the tax returns together, but you will still be able to calculate any credits they may be eligible for.  Here is some information regarding preparing a return for a deceased person. https://turbotax.community.intuit.ca/replies/2647725