Parents and an adult child own a rental, what is the percentage of step-up basis for depreciation

Hi,

Parents and an adult child own a rental property in CA(community property state).

!) After husband passed, wife and child each gets 50% of the step-up basis.  The rental gets 100% of the Fair Market Value(FMV) or 1/3 of the FMV as the step-up basis?

2) A few years later, wife passed. Child gets 100% of the step up basis. The rental gets 50% of the FMV or 100% of the FMV?

Thanks.