If your sister qualifies to be your dependent, it will have no bearing on her Social Security benefits or on your father's old age Social Security benefits.
You can claim a child as a
dependent on your 2018 taxes as long as they meet the following requirements:
- They are related to you.
- They aren't claimed as a
dependent by someone else.
- They are a U.S. citizen,
resident alien, national, or a Canadian or Mexican resident.
- They aren’t filing a joint
return with their spouse.
- They are under the age of 19
(or 24 for full-time students).
- They live with you for more
than half the year.
TurboTax will ask you a series of questions to be certain your sister qualifies as a dependent.