We do not have enough information about you or your sister to know if you could be eligible for earned income credit. Try the IRS tool to see if you are eligible:
https://www.irs.gov/credits-deductions/individuals/earned-income-tax-credit/use-the-eitc-assistant
If your sister is your dependent, you can get the $500 credit for other dependents if you claim her, and if you are paying someone to take care of her so that you can work, you may be able to get the dependent care credit. If you pay for her medical expenses you may include your out of pocket medical expenses if you itemize deductions.
IRS interview to help determine who can be claimed:
https://www.irs.gov/help/ita/who-can-i-claim-as-a-dependent
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
