"So you don't think I'm a match for Lucius Malfoy?" said Mr. Weasley indignantly, but he was distracted almost at once by sight of Hermione's parents, who were standing nervously by the counter that ran along the great marble Hall, waiting for Hermione to introduce them.
Harry Potter and the Chamber of Secrets, chapter 4
E sabemos que os Dursley também têm lembranças do mundo bruxo, e Petúnia sabia tudo sobre magia quando Lily estava na escola:
"...I'm sorry, Tuney, I'm sorry! Listen -" She caught her sister's hand and held tight to it, even though Petunia tried to pull away. "Maybe once I'm there - no, listen, Tuney! Maybe once I'm there, I'll be able to go to Professor Dumbledore and persuade him to change his mind!"
Harry Potter and the Deathly Hallows, chapter 33
...
"Knew?" shrieked Aunt Petunia suddenly. "Knew! Of course we knew! How could you not be, my dratted sister being what she was? Oh, she got a letter just like that and disappeared off to that - that school - and came home every vacation with her pockets full of frog spawn, turning teacups into rats. I was the only one who saw her for what she was - a freak! But for my mother and father, oh no, it was Lily this and Lily that, they were proud of having a witch in the family!"
Harry Potter and the Sorcerer's Stone, chapter 4
Veja também answer , que tem outro excelente exemplo.