The speaker is talking to a young girl who doesn't realize how remarkable she is. The opening images are big and vivid: galaxies in her veins, electricity coming off her hair. She seems almost cosmic, full of energy and light. Then the poem turns on "And yet," and the lines shrink into short, hesitant fragments, "She believes / She is / Ordinary." The breaks make her self-doubt feel small and halting, a sharp contrast with the grand imagery before it.
The speaker's tone is tender but firm. Calling her "sweet child" sounds protective and affectionate, and the claim that nothing is ordinary "about a revolution" suggests her difference is a kind of power. The ending is a question, "Don't you?", which invites her, and the reader, to act rather than simply be told. The mood is warm, encouraging, and quietly rousing, like a friend who believes in you before you do.