She must have unearned income greater than $2,200. If a child’s unearned income is more than $2,200, Form 8615 is used to compute the child’s tax. File Form 8615 with the child’s return if:
- The child has more than $2,200 of unearned income,
- The child is required to file a tax return (if the parents qualify and elect to report the child’s income on their return, the child is not required to file a return or
- The child meets certain age requirements. Under 18, Kiddie Tax Applies. Age 18-23, KiddieTax applies unless child provides more than 1/2 support with earned income.
- At least one of the child’s parents was alive at the end of the tax year, and the child does not file a joint return.
If the filing requirements are met, Form 8615 is required even if the child is not a dependent.
You mentioned is is being claimed by someone else. If she is married, it would be best to file a joint return with her spouse.
