Thanks to River

"The second time we meet her, we thought she was a stalker. It's not like she was following us around, it was the fact that she knew everything about us, despite the fact that she was a muggle. Her name was River Jones," A muggle girl come in to Fred's life with 7 interesting books, the Order reads the books. And who is this River and how does she have the 7HP t in 5th year