What is the magnitude and direction of the gravitational force that acts on a woman who weighs 500 N at the surface of Earth?

The magnitude is ##500N## and the direction is towards the center of the Earth.

We normally call the gravitational force "Weight" evaluated as the product of the mass of the object (in ##kg##) and the of gravity (##g=9.8m/s^2##) and it is measured in Newtons.

This force acts on us AND on the Earth.

So basically the Earth attracts us and we attract the Earth (Action-Reaction pair).