I have had an unpleasant experience with this issue as well. I am trying to file 2022 for my parents, my mother passed away in March of that year. Running into the same issue you did with the information required to start either return, I (stupidly) downloaded (and paid for) a desktop version, and did my mom's draft return so I could start my dad's in the online version. When you start the returns, TurboTax says:
We're sorry for your loss. We'll do our best to make the preparation of Bill's and Suzy's tax returns as straightforward as possible for you. You'll need to complete Peter's and Jean's returns separately because one of them passed away during the tax year.
You can then choose which return to start first. All of this gives the impression that you can prepare the returns as you would normally do, but one can be e-filed, the other must be printed and mailed. This would be great because then the information required for both returns can be shared and there is no need to enter things in twice on a separate return.
BUT THAT IS NOT WHAT ACTUALLY HAPPENS!!!!!!
I completed my father's return and before filing, paid for TWO TurboTax Premier Online 2022 then filed my dad's return. But that's where it ends. ZERO option to continue with my mom's return. I understand the returns have to be completed and filed separately, but, in my opinion, the online version gives you every impression that the returns can at least be prepared together, when it turns out they cannot.
I spent over an hour on the phone talking to a rep about this. All I got in the end was a product code for a free return to do my mom's, having to enter in a bunch of info that should already be there. I am disappointed.
Good luck!
