回複：托人將女兒從國內帶回美國，需要美國辦手續？

Your need write a letter indicating that your daughter will travel to USA with someone (name, DOB), and that they have your permission to do so. this letter need signiture of both you and your spouse. This letter is also need be notarized.
The US Custom may or may not require this letter. But if they require it, your relative should show it.