What's the best way to enter a 1099 from a brokerage UTMA under child's SSN? when importing, it appears to add the info as income, div & gain for the parent

If the child has capital gains you cannot report the child's income on the parent's tax return. You have to file a separate tax return for the child.

As rjs states above, you can't add regular capital gains in an UTMA account to a parent's return.

However, if the child has only capital gains distributions from a mutual fund (reported on 1099-DIV) then the income can be reported on the parent's return. 

However, you can't import this type of data - you'd need to manually input in the area for child's income reported on parent return.  This goes in the section for "child's income" under Less Common Income in TurboTax.