It depends. If her income consists of more than $2100 in unearned income and meets certain other requirements, then she would be required to file Form 8615. Please refer to page 1 of the IRS form instructions under the heading, "unearned income" for additional information. This is a good FAQ about unearned income. https://ttlc.intuit.com/replies/4790636
When children have investment income, the IRS gets concerned that parent's might be putting their own investments in their kid's name since kid's are taxed at a lower rate than adults. Please refer to the following FAQ for additional information. https://ttlc.intuit.com/replies/3301446
