Over the years, it becomes easier to forget Lily. During the summer, Petunia volunteers at an elderly home nearby and spends her days reading to sleeping old men while Lily locks herself in her room to study. At first, Petunia tries because she’s eldest and doesn’t want their parents to blame her for upsetting their perfect little Lily. She soon stops trying, though, as she and her sister drift farther apart. When Lily is with the family, she’s never quite part of them anymore. She looks at them as if she’s at a zoo and not quite sure what she’s seeing.
Their parents never notice, so enamored with Lily that she can do no wrong, but Petunia notices. Lily is ashamed of them and thinks herself so important just because she can wave a stick around and make things happen. It makes her jealousy turn to hatred as she gets older, and Lily pulls further away from them. She’s no longer an Evans, she’s one of them.
When they were children, they were close friends. Not everyone knows that, but it’s true. They played together in the garden, making up stories about witches and dragons that made them giggle until, one day, Lily had a chance to make those stories real, leaving Petunia behind without ever caring. Petunia keeps those happier memories private, never sharing them even with Vernon after they start dating. When he asks about her family, she tells him ‘I’m an only child’ because, in many ways, it’s the truth.