I grew up sailing on a cruiser every weekend and sometimes for weeks/months at a time. I've lived and traveled in Europe and South America. My answer? No. 
Not until many years of maturing and training have taken place. Dad needs to get his head out of her glory and rejoin the real world.
Not unless she's licensed to carry concealed and extremely well trained in self defense, rescue from both ends of the situation, radio operations, navigational mathematics, astronomy, survival in extreme situations and of course, sailing above and beyond the average cruising sailor. And let's not forget social skills in foreign countries, language skills, ability to shop and cook....well, the list goes on. 
What I see is my nephew in the US Coast Guard risking his life to rescue another starry-eyed sailor who wants to circumnavigate the world.