The Harry Potter Books Almost Included a Weasley Cousin Who Would Have Been a Total Game Changer

Mafalda was the daughter of the "second cousin who's a stockbroker" mentioned in Philosopher's Stone. This stockbroker had been very rude to Mr. and Mrs. Weasley in the past, but now he and his (Muggle) wife had inconveniently produced a witch, they came back to the Weasleys asking for their help in introducing her to wizarding society before she starts at Hogwarts. The Weasleys agreed to take her for part of the summer, including the Quidditch World Cup, but regretted this almost immediately. Mrs. Weasley suspected that Mafalda's parents simply wanted to get rid of her for a while because she turns out to be the most unpleasant child Mrs. Weasley has ever met.

Mafalda was supposed to convey certain information about the Death Eaters to Harry, Ron, and Hermione because as a nosy, eavesdropping Slytherin who likes to impress, she does not keep her mouth shut when she overhears their sons and daughters talking. Unfortunately, however bright I made her, there were obvious limitations to what an 11- year-old closeted at school could discover, whereas Rita Skeeter, whom I subsequently built up to fulfill Mafalda's function, was much more flexible.

The best thing about Mafalda was that she was a match for Hermione. To the latter's horror, Mafalda was highly gifted and a real show-off, so that Hermione was torn between deploring the rule-breaking and longing to join in and beat her.