The sentence that does not belong as a supporting detail for the topic sentence "My sister has a chocolate craze" is sentence E: "Chocolates are expensive nowadays." This sentence does not provide any additional information about the extent of the sister's chocolate craze or how it affects her behavior, and is therefore not relevant to the topic sentence. The other sentences provide specific details about the sister's behavior and habits related to chocolate consumption, and support the idea that she has a strong preference for chocolate.