I am sorry for your loss.
With respect to how this should have been handled in the 2020 tax year, read the post by @AmeliesUncle in the thread below (perhaps he will also comment here).
Solved: My wife died in 2022. In Turbotax, how can I Step Up the cost base of our rental property to...
You can probably rectify any foregone depreciation deductions on the one-half you acquired from your wife by filing Form 3115 (but that form will most likely require professional guidance).
