"James was amused by
Petunia frequently referred to witches and wizards as "freaks". However, deep down never did she forget that Harry was her sister's son. She begrudgingly gave him room and board for sixteen years because she knew that her home was the only place that he could be safe from the hands of Voldemort.
When Petunia opened the door, she hardly breathed because she thought it was her sister and her husband back from the dead until she saw Harry's eyes.
When Lily received a letter from Hogwarts confirming that she was a witch, Petunia wrote to Albus Dumbledore asking if she could also study there too. Dumbledore responded saying that Petunia could not study at Hogwarts due to her being a Muggle and even though he responded kindly, Petunia felt hurt and left out.
She made a promise to Dumbledore
As Lily's last remaining blood relative, if Petunia were to take Harry in it would seal the enchantment and provide him with protection from Voldemort.
No doubt Petunia would have been saddened by the news of Lily's death but those complicated emotions – grief, regret and unresolved jealousy – were probably buried in the distractions of housework, gossip and pandering to her son Dudley's every whim.
Her last line there is, "You didn't just lose a mother that night in Godric's Hollow, you know. I lost a sister." Since Aunt Petunia usually prefers not to acknowledge Harry's mother at all, it's a surprisingly sweet moment. In the book, she uses her last words to say "Well — goodbye" to Harry.
No, she is not, she is not a Squib. She is a Muggle.
Petunia wanted to be a witch: Rowling reveals that, “Petunia had some latent feelings of guilt about the way she had cut Lily (whom she knew, in her secret heart, had always loved her) out of her life.” She also says that Petunia always held out hope that she would show signs of magic “and be spirited off to Hogwarts.”
Letter information
Although Dumbledore wrote a reply letter very kindly, which refused her entry on the grounds of her being a Muggle, Petunia still felt left out. This caused Petunia to cut off contact with Lily, her sister and the wizarding world.
And the Dursleys didn't attend the Potters' marriage ceremony. "[Petunia] and Vernon chose not to attend Lily and James' wedding.
6 The Dursleys Kept Harry's Baby Blanket
Dudley found it in Aunt Petunia's belongings after she passed away and sent it to Harry. This insinuates that Petunia held onto it for years, in spite of her resentment toward the Wizarding World and Harry, because it was another piece of Lily.
According to Pottermore, the last time Vernon and Petunia ever saw Harry was the day they left Privet Dr. in Deathly Hallows (See “15 times Harry Ruined the Dursleys' Day #15). Why could Harry just not disapparate from The Dursley's to the Burrow on the night he left the last time?
"The first meeting between Lily, her boyfriend James Potter, and the engaged couple, went badly, and the relationship nosedived from there," Rowling revealed. Rowling adds that Vernon hated Harry because he saw father James in him, much in the same way that Snape does.
For the same reason Lily was a red head and Petunia was blond: by accident of genetics. Magical ability, like red hair, is a recessive mutation. It can appear spontaneously or be passed down from an ancestor. The more people in the family who do not have the mutation, the less likely it is to be expressed.
Harry and Dudley maintained a relationship:
The once-estranged cousins made amends after Dudley's admission that Harry wasn't a “waste of space” and remained on “Christmas-card terms” as they grew older. However, their relationship never blossomed into a true friendship.
'Remember my last'
Petunia's disdain for Harry was most likely born from a long-standing jealousy of her magical sister, Lily. A Howler from Dumbledore, addressed to Petunia, said 'Remember my last' – no doubt referring to the letter which he left with baby Harry, on the doorstep of Privet Drive.
Petunia tried to hit Harry with a frying pan which thankfully Harry dodged.
Dear Petunia, It is with great sadness that I must inform you of the death of your sister and her husband. They were murdered by a Dark wizard known as Lord Voldemort, whose cruelty and violence they had been fighting for years. I tried my best to protect them, but, alas, I regret to say that I failed.
The two children of Dudley Dursley and his wife were Muggles. They were occasionally visited by their magical second cousins, the two sons and daughter of their father's cousin Harry Potter. It is unknown whether they knew of their cousins' magical heritage.
While Vernon consistently praised his son as if he was extremely masculine and robust, Petunia infantilised Dudley, calling him "Diddykins" well in to his teen years, appearing heartbroken to have to put Dudley on a much-needed diet and even bursting into tears when Dudley showed marginal affection for Harry.
Simply put, Harry couldn't be harmed by the Dark Lord at the Dursley household because it was the place where his mother's blood dwelled. Chapter 37 of Harry Potter and the Order of the Phoenix reveals Dumbledore himself explained what he'd done in the letter that he left with Harry on Petunia's doorstep.
Harry was supposedly on amicable terms with the Dursley family, claiming they were on his Christmas card list. Uncle Vernon and Aunt Petunia (who had secretly longed for magic herself) didn't see much of their nephew, for obvious reasons.
Hagrid appears at the hut and gives Harry his letter in person, leading Petunia to admit she knew Harry was a wizard and that she and Vernon had sworn to stamp the magic out of Harry when they took him in. She claims that her sister's (Harry's mother's) magical abilities made her a freak.
This Howler was written by Albus Dumbledore to Petunia Dursley on 2 August, 1995, to remind her "of the pact she had sealed by taking Harry Potter" into her home. This Howler ensured Harry Potter continued to reside at the Dursley residence.