wordplay - A seven letter word denoting a woman

I am a seven letter word.

The first two letters denote men.

The first three letters denote women.

The first four letters denote men.

The whole seven letters denote women.

Who am I?

Answer

The answer is

Heroine

Explanation follows

He - denotes men
Her - denotes women
Hero - denotes men
Heroine - denotes women