My 4 Year old received a 1099-B for her custodial account

My 4 year old owned some 21st Century Fox stock in her custodial account in 2019.  21st Century fox was acquired by Disney, this merger generated a gain of under $6 in her account. The transaction is reported on a Form 1099-B Proceeds From Brokerage and Barter Exchange Transactions.  She has no other income, earned or otherwise.  I'm not sure if I still have to file a tax return for her, since this is classified as a capital gain, and not interest/dividends?

 

Would really appreciate any advice.  Thanks!