Sorry for your loss. I lost my husband in 2023.
You can file a Joint return as normal the year your spouse died. For the next two years following a husband's or wife's death, the surviving spouse can file as a qualifying widow or widower if they have a qualifying child. That basically lets you continue to use the same tax brackets that apply to married-filing-jointly returns. After the year of death if you don't have a child you file as Single. To file Single you have to start over with a new return and new account. And don't transfer from the Joint return.
See How to file if your spouse recently died
https://ttlc.intuit.com/turbotax-support/en-us/help-article/small-business-processes/file-return-spo...
You can start another return in TurboTax Online by:
Logging out if you are in your account
Choose what TurboTax Online product you want to use for the second return
https://turbotax.intuit.com/personal-taxes/compare/online
Create your account screen
Set up a new login for the second return
Start working on the new return
I think you can continue taking the Capital Loss Carryover. You can manually enter it.
