Petunia and Lily had only been out of contact for about 3 years when Lily died, contradicting the movies' implication of a longer estrangement. Petunia being younger in the books changes her character and adds perspective to her hatred towards the wizarding world. Interestingly, Snape and Petunia share a common connection of regret over how they treated Lily, leading to their despising of Harry Potter.

The conflicted relationship between Lily and Petunia has always been sad, but a book detail that the Harry Potter movies changed makes it far more tragic. The sisters had been at odds with one other ever since they learned that Lily was a witch, and the series' first book revealed that they hadn't talked in the years leading up to Lily Potter's death. However, a subtle detail in the Harry Potter books and information on the Wizarding World website implies that Petunia Dursley and Lily Potter...