My fiancee and I are planning a trip to puerto rico, we want to take her daughter, all of us are US citizens.?

Question

Do we need any type of permission from her biological father to travel there? He refused to let her travel to other countries, but puerto rico is part of the US.

Answer 1

No, you don't,  it is no different than travelling to a neighboring state, or even to Hawaii or Alaska.  It is a domestic trip.