@divanailsalonsr- You're looking for a simple answer to a complex question. There isn't one.
Q. What age can a child can be an independent on tax return?
A. Simple answer: 19, if not a full time student. See full dependent rules at: https://turbotax.intuit.com/tax-tools/tax-tips/Family/Rules-for-Claiming-a-Dependent-on-Your-Tax-Ret...
Q. Is it better if she starts working to support more than half of her expenses starting first year of college or 12th grade?
A. Neither. It's highly unlikely someone under 19 would be self supporting or even a full time student under 24. The financial aid people are wary of young college students claiming independence.
Q. If she Gets 14k for financial aid* (scholarships/grants) and spent 10k om tuition and books. She has 4k as taxable income. Let say her dorm and food is another 5k. Does she need to make more than half of 4k to say that she support more than half of her expenses?
A. No. Scholarships and the expenses they pay are ignored in the dependent support calculation.
*Loans are treated differently from scholarships in the dependent support test. Co-signed loans are treated as parental support. Loans in the student's name only are self support.
