Unfortunately, once you have started preparing your returns together, there is no way to separate the returns. You would need to create a new return to prepare a separate return, which you can do by selecting “Start a New Return” from under “My Returns”. Once you have started your new return, you can select “View All Tax Returns” from under “My Returns”, and delete the unwanted return by clicking the small Trash Can next to it (or “Delete” underneath it, on mobile).
If you have TurboTax Live Assist & Review, here is how to talk to a Tax Expert: https://turbotax.community.intuit.ca/community/navigating-turbotax/help/i-m-using-turbotax-live-assi...
