If he was learning what she learned as a first year from the third years in her House, he wasn't learning anything that was correct or true. She had to conduct her own independent research in the medical books in her father's study when she was home between terms to discover they were wrong. Of course, considering the third years were Fred and George Weasley and their best friend Lee Jordan, it was highly probable that they only told the younger students in their House what they did as a joke. One never could tell with the Weasley twins.