I prepare my mother's taxes. She died in 2020 (non covid). I completed her 2020 taxes no problem. I sold her home in 2021. Now i'm doing her final tax report. Turbotax insists on me inputing her death date as if it occurred in 2021. Help.

You did not sell her home in 2021. If you were the beneficiary, you sold your inherited home. If you were the executor, you may be filing an estate return with k-1s for the beneficiaries. Your mother does not have a tax return after her year of death. Everything went into her estate or was passed through some other means, trust, POD, etc.

I am sorry for your loss.

You cannot file a personal return for a decedent after the year they passed.   So who exactly sold the home ?   You or the estate ?