After you file

@KrisD15 

 

I have 5 year old twins.

 

this is how Turbo Tax is filling in the amendment forms:

 

amended 1040

       dependent child A is the only listing

 

1040X 

       dependent child A - check for CTC

       nondependent child B - no check for CTC

 

I guess technically it would be okay because on the 1040X, the CTC box is not checked for the nondependent child. BUT the IRS will not accept it since the nondependent child does not also appear on the amended 1040.