It sounds like you're subject to the "kiddie tax." The name "kiddie tax" is a holdover from the days when it only applied to children under 14. It's not just for kiddies anymore. The age limit has been raised to where it can apply to adult children who are still in school, but the name has stuck.
Your best course of action would be to wait until your parent has completed his or her tax return, so that you can enter the necessary information in your tax return. If necessary you can get a 6-month extension of time to file your return.
The alternative is to use estimates of the information from your parent's return. On the screens where you enter the amounts from your parent's return there is a box to check to indicate that the amount is estimated. But if you do that, after your parent files his or her tax return you would have to file an amended return with the actual amounts.
