If a child's only income is interest and dividends, the parents can choose to report it on the parents' return, in the "uncommon income" section.
However, if the child has any other income (capital gains, wages, prizes, etc.) then all the child's income must be reported on a separate return in the child's name. If you are using Turbotax online, you would have to log out as yourself and then create a new account for your child's return with a different user name and password (it can be linked to the same e-mail address).
