There is one situation in which you can claim your sister as a non-dependent, and that is for Earned Income Credit. If she was under 19 years old, or under 24 years old and a student, or any age and totally disabled, you may be able to claim your sister for Earned Income Credit. But to claim Earned Income Credit as a non-dependent, your sister will have to have provided at least 1/2 of her own support. If all of these conditions exist, you may input her information and state that she did provide at least half of her support. And you can only do this if no one else is allowed to claim her as a dependent.
Otherwise, you should either claim her as a dependent if she qualifies or remove her information from your return.
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