Sylvia faces an internal conflict of the character vs. self variety. When the hunter offers her ten dollars in order to reveal to him the location of the heron's nest, she cannot help but be tempted by it.
No amount of thought, that night, could decide how many wished-for treasures the ten dollars, so lightly spoken of, would buy.
Not only is Sylvia tempted by the thought of all the treasures one might buy with the ten dollar reward, but she is beginning to think differently of the young man who first frightened her. Now, she thinks he's a "friendly lad" who is proving "to be most kind and sympathetic." He tells her lots of things about the animals she loves, and he even makes her a gift of a jack-knife that she thinks of as a great treasure. She no longer fears him, except when he shoots a bird, and she begins to see him with a kind of "loving admiration. She had never seen anybody so charming and delightful [...]." In her desire to please the hunter, she considers the tall tree on the wood's edge, thinking,
[...] why, if one climbed it at break of day, could not one see all the world, and easily discover from whence the white heron flew, and mark the place, and find the hidden nest?
So she climbs the tree the next morning, watching hawks and feeling "as if she too could go flying away among the clouds." Sylvia spots the heron too, silent as she watches him perch and call back to his mate in the nest. "She knows his secret now [...]," and she wonders, with some excitement, what her hunter will say when she tells him where the heron lives. However, when the moment comes, she cannot speak.
He can make them rich with money; he has promised it, and they are poor now. He is so worth making happy, and he waits to hear the story she can tell. No, she must keep silence! What is it that suddenly forbids her and makes her dumb? Has she been nine years growing and now, when the great world for the first time puts out a hand to her, must she thrust it aside for a bird's sake? [...] [S]he remembers how the white heron came flying through the golden air and how they watched the sea and the morning together, and Sylvia cannot speak; she cannot tell the heron's secret and give its life away.
On one hand, she would tell the hunter where the heron lives because she wants to make him happy as well as relieve her poverty; on the other hand, she doesn't want to tell the heron's secret because she wants to protect it. She is torn, momentarily, between these two conflicting desires before she, ultimately, decides that she cannot betray the heron; she knows telling its secret will mean certain death for the beautiful bird with whom she feels a kind of kindred connection.