You will have to wait for her return to be fully processed and refund received. Then you must amend to show she's a dependent.
Due to this error, your return must be paper filed. There is no way to e-file it even after amending her return. How long to wait to mail to avoid IRS notices about claiming her when she claimed herself is unknown. (if mailed immediately the IRS will have your return before it gets and processes her amended return). TurboTax tax tool says the 1040X won't be ready until mid-February
When you paper file your return be sure to read the filing instructions W-2s and withholding forms must be attached. Federal and state returns must be mailed separately and to the address TurboTax indicates.
This answer has been verified for accuracy by an Intuit expert employee
