@scrabbleman she probably had a caster or something who could teleport with her army that was wiped out. You know, the few hundreds of friends and colleagues she has worked with for who knows how long and are now dead.
Maybe the demon king wanted to save some time.
Right now they need two tickets, if the heroine is already there, the hero only needs to farm for one... and saves it a lot faster, since the heroine won't spend it all right away.