Dear Mr Dumbledore,
I am writing to you because I feel that you will best comprehend this situation. I have recently been concerned with the tragic incident involving my sister, despite promising myself that I would not dwell on it.

Petunia read back what she had already written and shook her head. This would never do – writing to a man she barely knew, and then letting him into her life? More importantly, she knew that she would be letting him into her history.

The front door slammed, causing Petunia to jump in surprise. The voices of her mother and sister floated up the stair through the open door.
'Hello dear! Have you had a good day? How are Amelia, and Samuel, and your other friends?'
'Who cares!?' Lily stomped up the stairs fuming, and muttering to herself angrily. Storming into the bedroom, she stopped dead in her tracks when she saw her sister calmly reading on the edge of her bed.
Petunia looked up at her, then without a word looked back to the book, turning a page as she did so. Lily threw her bag onto her bed, and sat down at the dressing table, brushing her already perfect hair. She was watching Petunia in the mirror wordlessly, occasionally eating a chocolate from the box next to her.
Lily sighed impatiently and strode over to the wardrobe where she began throwing clothes onto her bed. Petunia looked up as clothes flew past her nose. 'Do you have to do that now?'
Lily turned on her furiously. 'Don't you have anything better to do than watch me?'
'I was reading actually, but it's become… somewhat loud in here, strangely.'
'Oh shut up and get a life.'
'I'll get a life as soon as you prove to me it's better than what I've got now.'
Lily laughed cruelly. 'Pre-learning your comebacks now? Is that what your reading – 'Arguing for idiots'?'
Petunia held up the book to show the cover to her sister. 'No, it appears not. As you can see this is 'A Midsummer Night's Dream'.'
'You're reading school books in the holidays? You loser!'
'It's not a school book, it's a piece of 16th Century literature, which I chose to read. Besides, you read all of your school books in the holidays too.' Petunia returned her interest to Shakespeare, but she could feel Lily's gaze burning into her. She turned the page, and clothes started to fly about the room once more.
Lily's muffled voice came out of the wardrobe as a green jumper hit the floor, missing the bed. 'I can't believe you waste your time hanging around at home all summer, living out of books!' She retreated back into the room holding a pair of jeans before continuing, 'But of course you don't have any friends to see anyway…'
She looked at the jeans, and then threw them onto the growing pile on the bed, now rummaging in a huge chest of drawers. Petunia turned another page of her book, paying no attention to Lily.
Her older sister continued to talk, now warming to one of her favourite subjects. 'You're so brainless sometimes, I can't believe we're immersed in the same gene pool, you know that?'
Petunia put her book in her lap and looked at Lily, who was observing her over a green t-shirt she was holding. 'Does it make you feel any better, putting me down all the time?' She tried to sound confident and pitying, but suspected that she sounded rather pathetic.
'Oh don't give me that, Petunia! I mean, look at you! Why would anyone bother with that!?' Petunia went back to staring at her book and ignoring her sister, but her eyes were no longer taking in the words on the page. 'You're nothing, and you know it!'
'That's no true,' replied Petunia steadily, her jaw set firmly. She was determined not to cry.
Lily laughed heartlessly, and maliciously retorted, 'You don't seriously believe that do you? Talk about disillusioned, Petunia! You are totally worthless! You'll never amount to anything in your whole life!'
Petunia knew that her sister was just picking at her insecurities, her paranoia. Unfortunately, it was working. Both of the girls knew that it was. Lily was metaphorically circling her prey, looking for the right sport, waiting for the right moment to deliver the fatal blow.
Petunia felt herself tense as Lily opened her mouth, her poisoned tongue set to destroy her own flesh and blood. 'Poor Petunia… never good enough for anything. Such a shame that you aren't learning magic; you can't even defend yourself, can you?'
Petunia looked up from the book in her lap, towards her sister who was turning her wand over in the hands thoughtfully; salt in the proverbial wound. 'Shut up Lily, you're not allowed to use it outside that freak school anyway.'
'Are you so sure about that, little sister?' Lily's eyes flashed dangerously, as she walked back and forth across her sister's eye line. Petunia felt fear actually rise within her. She looked down again, but Lily had already sensed how threatened she felt. 'Well now, you aren't sure are you?' She paused, walking closer and leaning in to her sister's face. 'Luckily for you, dear sister, this year I am banned from using magic in the holidays.' Petunia failed to disguised her relief, as Lily went on, 'It's only small relief, Petunia. Next year I can take my Apparation exam and use magic at home. I'll be of a responsible age, you know.' She stood up again laughing.
Petunia experienced a wave of hatred flowing through her, and she stood up too, vaguely aware of her book sliding off her lap and landing on the bedroom carpet with a dull thud. 'Look you,' she growled, her voice shaking in anger, 'You may have been born first and got into that freak school, but that doesn't give you the right to push me around. OK, I don't do magic and all that hocus pocus you do, for nine months every year! I do normal qualifications which will get me a normal job. I'm bloody good at what I do, so don't tell me I'm worthless!'
Before Lily could react, Petunia pushed past her into the hallway and entered the bathroom, slamming the door behind her. She turned the key in the lock and sat down on the edge of the bath with a sigh. She hated the arguments. She had watched her friends at school with their siblings, and they seemed to get along at least some of the time. It seemed to her that she and Lily's moments of truce were rare, and getting much less frequent as well.
She stood up and stared at her reflection in the cabinet mirror over the sink. She jumped as a noise like a whip crack reverberated from the hallway behind her. Holding onto the sink for support with one hand, and her chest with the other, she listened for more noise.
Just as she was deciding it must be next door's car backfiring again, she heard the distinct low murmur of voices in her room; a man was talking to her sister.
'I'm going mad,' she told herself as she noisily ran a bath; covering the noise of another bang outside the door. Sighing for what felt like the hundredth time that day, Petunia lay back in the steaming hot water and closed her eyes. 'That magic will be the death of her,' she concluded as the burning steam enveloped her; and she thought of her sister no more.

Her childhood with Lily was a complicated and unhappy one. Re-reading her letter again, Petunia decided that letting people into her world was probably a bad idea. Besides, she had no idea how to contact this man!
She looked at the grand fireplace next to her. She was glad that Vernon had not yet bought an electric one, as there was nothing quite like watching the flames eat at one another, into non-existence.
She looked away and scrunched up her letter into a little ball, aiming it in the general direction of the fireplace. She was shocked to hear a man's voice exclaim 'Ouch!', and for the paper to bounce back onto the carpet.
Looking at the fire, she let out a startled shriek as a man stepped over the grate, brushing ash off the black travelling cloak around his shoulders. He was a prominent figure; tall and magnificent, but he appeared quite old and wise as well. A long grey beard lay across his chest, and his equally long hair was a mixture of grey and white, catching the light of the dancing fire.
He stooped to the floor and picked up the paper at his feet. Smoothing it out, he surveyed the writing through half-moon glasses, which were balanced precariously on his long crooked nose.
He looked up at Petunia who was sitting bolt upright, still in shock that a man appeared to have walked out of her fireplace. 'Allow me to introduce myself, Mrs Dursley,' he said. 'My name is Albus Dumbledore.'

Hello, my adoring fans! hee hee Yes, I've updated again - our first flashback! I'm not too sure about it, because I don't think this is the best I've ever written, but I've posted it because hopefully it will keep th story going. Constructive criticism is VERY welcome, so please R&R!

DISCLAIMER: I don't really own anything here, J.K.Rowling invented Harry Potter stuff, I'm just fiddling with it and looking at Petunia's POV.