I can't even begin to image how you feel...But...I think you should focus on what you able to control right at this moment:
You can bring 'both' your girls home together!
I know it is not actually bringing Katie back home, but in a sense you are bringing her back to the family where she belongs and at the same time you are bringing home your newest addition. You, Jim, Codie, Katie and 'Baby Girl - not yet named
' are all ONE FAMILY.
Please try to be Happy together once again...