Petunia Evans Dursley

Early Life (1958-1971)
Petunia Evans Dursley was born in the spring of 1958 in Cokeworth to Harry Evans and Mrs. Evans.

Her younger sister is Lily Evans Potter.

Her sister's childhood best friend, Severus Snape, introduced her to the magical world, and she was aware of her sister's Muggleborn status long before her letter from Hogwarts arrived, often calling her a "freak".

Sometime in June of 1971, Minerva McGonagall met with the Evans Family and convinced them to send Lily to Hogwarts, in order to train her abilities.

Petunia begged Dumbledore to allow her entrance as well, but he denied her request upon the grounds that she had no magical abilities, and therefore, would not perform well in school.

Hogwarts Years (1971-1978)
She disliked everything having to do with Lily's education at Hogwarts and grew further and further removed from her sister, refusing to allow her to attend her wedding to Vernon Dursley in the spring of 1978.

When her sister began dating James Potter in January of 1978, Petunia reacted to the news by calling James a "no good, unemployed drunk", which Lily reacted to by bringing James by during Easter Holidays in 1978 and proving empirically that, while a little rough around the edges, her boyfriend was hardly what Petunia thought he was.

Petunia moved into Number Four, Privet Drive after her marriage in the summer of 1978 and did not return to the Evans house frequently before her parents' death.

First War (1978-1981)
Lily and James married in the summer of 1979. Petunia and Vernon, despite being invited by James, did not attend.

She was alerted to the severity of the First War and warned that she and Vernon may be targeted, and Petunia was worried for her sister's life to a great extent, though she refused to communicate it. Her only child and son, Dudley Vernon Dursley, was born in June of 1980, a month before his cousin, Harry.

She was happy to learn that Lord Voldemort had been defeated, ensuring the safety of her sister, but especially so because they sent the letter through Muggle post and now had a regular mailing address, as "normal people should".

Post War Years (1981-?)
Petunia also had four more nieces and nephews through her sister, Lily -- Sarah Emmeline Potter(born February 1984), and the triplets-- Anne Marie Potter(born December 1984), Andrew Ryan Potter(born December 1984) and Matthew Nicholas Potter(born December 1984).

She met them for the first time during Dudley's fifth birthday party, during which she expressed concern that James was a negligent father and that Lily couldn't possibly handle all of her children by herself.