Starvecrow Farm by Stanley J. Weyman

Henrietta crouched beside the lamp, lulling the child from time to time with a murmured word. She held the boy, whom she had come to save, tight in her arms; and the thought that she held him was bliss to her, though poisoned bliss. Whatever happened he would learn that she had reached the child. He would know-even if the worst came-what she had done for him. But the worst must not come. Were she once in the open under the stars, how quickly could she flee down the road with this light burden in her arms-down the road until she saw the star-sprinkled lake spread below her! In twenty minutes, were she outside, she might be safe. In twenty minutes, only twenty minutes, she might place the child in his arms, she might read the joy in his eyes, and hear words-ah, so unlike those which she had heard from him!

There were only two doors between herself and freedom. Her heart beat at the thought. In twenty minutes how different it might be with her-in twenty minutes, were she at liberty!