You have to file by mail. Even if your daughter amended her return, it takes months for an amended return to be processed. Your 2018 return claiming her as your dependent must be printed, signed and mailed.
When you mail a tax return, you need to attach any documents showing tax withheld, such as your W-2’s or any 1099’s. Use a mailing service that will track it, such as UPS or certified mail so you will know the IRS and/or your state received the return.
You are far from alone--many parents have inexperienced dependents with first jobs who file tax returns without realizing they have to say they can be claimed as someone else's dependent.
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**