Unfortunately, once you have started preparing your return together with your spouse, then there is no way to separate the returns. If you have selected the option to prepare your return for “My spouse/partner and me” at the start of the return, it cannot be changed once you click continue. You have to start a new return.
To start a new tax return in TurboTax Online, sign in to your account, then select Start a new return from the top of the left side menu.
However, if your spouse is not reporting much income this year (or none at all), she may still want to file a return, as she may be eligible for federal and provincial benefits.
For more information, please review the links below from TurboTax Canada.
How do I start a new tax return in the online edition of TurboTax?
Who Is Required to File an Income Tax Return?
Thank you for choosing TurboTax.