Women need more money than men. They buy four times as many clothes as men, and spend ten times as much as men on 'Beautifying" themselves with perfumes, makeup, hair styling and so on, and many times more than men on decoration of their bodies with baubles, bangles and bright shiny beads. They also discard used clothes at a rate many times that of men, and cost more to feed with their diets of special fad foods.
So they need more money - it's as simple as that.