DawnC0Answer
Level 12
Jun 5, 2019 12:06 AM UTC
Yes, if you want to claim a dependent that has already been claimed, you will need to select File by Mail as your filing method; you won't be able to e-file. https://ttlc.intuit.com/replies/3401713
She should file an amended return to indicate she is claimed on another return, but you will still need to file by mail.