Unlike in some other countries, Canada doesn't have joint filing for spouses/partners. TurboTax just allows you to prepare returns together with your spouse to make it easier to claim credits and maximize deductions. Also, since your return has already been NETFILEd, you would have to use your existing return if you want to ReFile.
You can create a individual return for your wife and file it. Then once you have your Notice Of Assessment, you can ReFile your return.