About my ammened return

Yes, sometimes removing wages from your tax return will decrease your refund. This can happen if you qualify for Earned Income Credit, and you own income is less than about $15,000, or in cases where you qualify for more than one tax credit. 

Your daughter's W-2 may have had some federal tax withheld in box 2. Removing her W-2 will take that withholding off your return. 

Taking her W-2 off your return is the only correct thing you can do. If you didn't fix that yourself, the IRS would catch it and bill you for the additional tax. 

You can file a tax return for your daughter and she may get a refund. Just be sure to check the box under My Info that she is a dependent on someone else's tax return.