If your return was rejected when you tried to E-File, then you have NOT filed your tax return. There is no need to Amend. There would be no record right now of your filing a return.
The term "Amend" a return is used when a change is needed to be made to a return after the IRS had received, processed and sent you your refund (or collected tax due.)
So, if you need to remove a dependent and then add another to your 2017, you can make those changes to your return, in Turbo Tax and then go ahead and E-File.
