Iris saw Hiro go out to practice his combat and followed him. While the advent had no such practices (nor need for any such practice) such as close range combat, preferring their psionic enlightenment, Iris needed to speak with him. He was, after all, the leader of Planetary defence and through that ultimately her commander. 

"Leader Hiro," she spoke as she walked out into the field he was in, "If we may, the unity wishes to discuss the matter of the new threat."