Your dependent would need to file their own return to report their W-2.
They will also need their own TurboTax Online Account to do this.
Each Online Return is identified by a Unique Username
You may use the same email address and phone number as your account.
You may have up to 5 accounts linked to a single email address.
They just need to indicate that can be claimed as a dependent in their Personal Info by answering Yes to the question
Someone else can claim me as a dependent on their tax return.
They may qualify for the TurboTax Freedom edition here:
I hope this helps