In the video below we will see a man force a woman into a car. Without knowing any of the background of the video we can learn some good lessons. There are indicators which should cause a heightened sense of awareness such as the man loitering on the corner and taking a peek around the corner as his target approached (it also suggests he had cased the location ahead of time).
Once he stopped her, she had an opportunity to bolt--until he grabbed her. And once he grabbed her she attempted to pull away and it became an uneven contest of strength.
How can a smaller person even the odds? The most vulnerable targets are the eyes, throat, and groin. Had she shifted her weight from pulling away to stepping into her attacker, she could have brought her weight to bear on a strike against any of the three preferred soft targets.