For the state of Florida, I will be going on a cruise on Carnival to the caribbean with my girlfriend. She will be 18 and I will be 23. The cruise terms state that you must be 21 to go alone, or be with someone 25+ if under 21. The age rule is waved if that person under 25 is your guardian. So the only way we can go on the cruise is if I am her guardian. Is assigning a guardian even possible if the person in question is 18 and now an adult? Would you be able to assign guardianship without the need of a court/judge? Can she assign me guardianship without her parents signatures? I will only need to be guardian for 8-10 days.