If you have already filed, yes it is too late. You will want to wait to get an accepted status from the IRS before preparing an amendment(change) to mail in to the IRS.
If you have not yet filed or your return is rejected by the IRS then you can absolutely add your daughter. Here's how:
- Click on the 'Personal Info' tab.
- Click on 'Add a dependent' box.
- Continue through the screens, entering the requested information.
