Is Petunia a witch?

that's right! she is a muggle who definetely really wanted to go to hogwarts with lilly and learn magic, but she couldn't... petunia tried hard to enter it so when she didn't, envious as she was, she prefered thinking that hogwarts was for freaks and so were the wizards. despite that, she still inside her wanted to become one of them and she kept in her mind every information about them she could... in a way, i feel kind of sorry for petunia, coz imagine your sister going to hogwarts and not u! i'd be jealous too! not so mean of course but i'd always feel a bit bad about the other world that i could never be part of...

There are no records in the books and no statements from Rowling stating that Petunia is a witch. She was never accepted for entry into Hogwarts, which can definitely lead to one believing that she was not a witch. She even wrote numerous letters to the Hogwarts headmaster requesting to be accepted like her sister, Lily had. Thus it can be logically assumed that Petunia's knowledge of the magical world comes from what she learned from observing and talking with Lily.

no she was not. only lily. petunia was definitely a muggle...