Maybe. The TurboTax program will ask you a series of questions to determine if her income needs to be reported on a tax return.
Dependents with unearned income, such as interest, dividends or capital gains, generally have to file their own tax return if the income is over $1,100 for 2020.
A parent can elect to claim the child's unearned income on the parent's return if certain criteria are met. Generally, the unearned income over the annual threshold ($2,200 in 2020) is taxed at the parent tax rate.
Please see TurboTax Help article Do I need to report my child's 1099-INT on my 2020 return? for guidance.
Claim it on your return, since it's only interest.
If his/her only income is from interest and dividends, Alaska PFD or capital gains distributions shown on a 1099-DIV, there is a provision for entering it on your return, using form 8814. Enter at Less common income / Child's income.
Using Form 8814 may even benefit a few parents who are not getting the full Child Tax Credit, as the credit will offset the total tax amount, including the child’s portion of the tax.
But, it may be best for him to file a separate return, if he has qualified dividends and capital gain distributions which could be taxed at a higher rate on the parent's return.