"Then, for your mother's share, the basis from the calculation above is reduced further by the total depreciation that was taken over the period of ownership and rental".
The depreciation "recapture" is taxed differently than the rest of the capital gain. In TurboTax (TT), do not include the depreciation reduction when you enter her basis. Instead make a separate entry for the depreciation taken over the years. The TT interview will guide you.
