Besides the fact you shouldn't be using Turbo Tax for "clients" he should be filing 2024 as Single unless he has a child and qualifies as a qualifying widower. So the deceased wife doesn't go on the return at all. Why are you trying to enter her into 2024?
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.
