If she was 23 on 12/31/19, then you must meet the requirements under a qualifying child in order to claim her as a dependent. If she was 24 on 12/31/19, then you must meet the requirements under a qualifying relative in order to claim her as a dependent. Please view the requirements in the Turbo Tax FAQ below.
https://turbotax.intuit.com/tax-tools/tax-tips/Family/Rules-for-Claiming-a-Dependent-on-Your-Tax-Ret...
