She is afraid of him. This is why:
Sylvia is a young girl from a crowded town who has moved to live with her grandmother in the country. She is driving home a stubborn old cow, and it is getting late. Sylvia is already "afraid of folks." She thinks about whether her town is still the same, and she recalls "the great red-faced boy who used to chase and frighten her made her hurry along the path to escape from the shadow of the trees."
Suddenly, Sylvia is "horror-stricken" to hear a boy's whistle not far away. The whistle is "determined, and somewhat agressive." Sylvia leaves her cow and steps into the bushes, but she's too late. The "enemy" calls out to her in a "cheerful" tone, and Sylvia trembles as she responds. He is a tall, young man that she will not look "boldly" at as he carries his gun.
She walks alongside the man, and he talks to her "kindly." Sylvia becomes even more alarmed when he asks if she thinks he might be able to spend the night at her house and go out gunning in the morning. Sylvia is worried that her grandmother will blame her for bringing him home.