It does not matter who buys the tickets ... only that the passengers Dividend Miles number is in the reservation before the flight goes out.
Plenty of reports on the board of USAirways Dividend Miles members at very tendere ages, including less than three years-old.
Put these two together and you may have a plan.
But double-check whether or not the challenge has to be done on USAirways flights, or whether American flights count, too. I am not up on this, but until recently it had to be on USAirways metal only. Because from Singapore, you either have a great opportunity ... or a real problem.