For the record, if an adult wants to single-hand it is their choice as long as they do not endanger others.
We are talking about solo circumnavigation by a minor not taking her best friend to the Mall up the road. There is a big difference. Even driving cross country, to use that example, she would have help nearby, repair services available, and safe places to wait for weather or get some rest.
We are talking sailing 24/7, alone, for how long? And for what? It won't guarantee her a happy life, or cure cancer. A line in a record book, until a kid with parents more irresponsible than her's allows their child to beat it.
This latest stunt strikes me as one of two possibilities:
A) an impulsive act by an immature person which was doomed from the start.
B) a coordinated act with multiple enablers and an unknown organizer.