Lily Evans: "You didn't think it [Hogwarts] was such a freak's school when you wrote to the Headmaster and begged him to take you."
Petunia Evans: "Beg? I didn't beg!"
Lily Evans: "I saw his reply. It was very kind."
— Lily and Petunia Evans on Petunia's Letter to Albus Dumbledore.[src]

Petunia Evans wrote a letter asking Albus Dumbledore whether she can go to Hogwarts to study with her witch sister, Lily Evans. Although Dumbledore wrote a reply letter very kindly, Petunia still felt left out. This caused Petunia to cut off contact with Lily, her sister and the Wizarding World.