Input Amount: 0.00546 mBTC
Output: blank
Fee for child: 0.00546 mBTC
No matter what I do, I get an error that says:
Cannot create child transaction:
The output value remaining after fee is too low.
Is 0.00546 mBTC the "input amount" or the "output amount"?
If it's the "input amount" then you will not be able to broadcast the transaction even if you manage to create it. Other nodes will reject it as any output amount smaller then 546 sats is considered a dust amount.
What wallet are you using? Because, afaik, Electrum will alow you to create the transaction but you will get a different error message when you broadcast it.