I have seven letters.
The first two stand for a boy.

The first three stand for a girl.

The first four stand for a brave boy.

But all my letters stand for a brave girl.

What word am I?

The anwser: he
                        her
                             hero
                                  heroine



(brave = γενναίος-α-ο, stand for =  αντιπροσωπεύω, συμβολίζω)