This happened to us when my 11-year-old (vaccinated) child tested positive on our last sea day on Harmony last month. Funny enough, we were also traveling with my parents (in another cabin, but adjoining) and my father tested positive too. My mom tested negative (until the day of disembarkation) so she stayed in the cabin when my dad was sent to the red zone. When my daughter tested positive, the rest of us (me, my wife, and my son) tested negative and so just I went down to the red zone with her while my wife and son could stay in the cabin. So I think it all kind of depends on whether the other family members test negative, but yes of course for a minor child one parent will have to accompany them.