A.N: This is an AU fic where Dudley has a younger sister. The Dursleys also care about Harry and treat him like a son. Aside from that, there's no difference from canon.

DISCLAIMER: Harry Potter does not belong to me. If it did, it would be nowhere near as brilliant as it is now. HP belongs to J.K Rowling, and I own this fanfic.

Petunia Dursley awoke on the morning of November 1st, 1981, to the sound of her infant son's screams.

"I'll go to him," Petunia mumbled sleepily to her husband Vernon as she slid out of bed. She padded along the landing to little Dudley's bedroom and picked the screaming one-year-old up in her arms.

"Who's my big boy?" Petunia cooed to him. "You are! You are!"

Dudley stopped his screams only to take a deep breath, then continued.

"Please quiet down, Dinky Duddykins!" Petunia said to the boy.

"Shan't!" Dudley yelled in his mother's ear. "SHAN'T!"

Petunia laughed fondly at her son - he had learned the new word the day before, and was now putting his new skill to use. She marvelled at how clever he was.

There was then another wail from behind her. She put Dudley back into his crib and went over to the crib on the other side of the room to pick up her daughter.

Petunia had gotten pregnant with her second child a mere month after Dudley's birth. Her daughter, Dana Dursley, had been born several months previously. Petunia rocked Dana back and forth several times, and she fell back asleep almost immediately. Smiling to herself, Petunia put Dana back into her crib and picked Dudley up again.

She brought Dudley down to the kitchen and popped him into his high chair. She then went over to the fridge, removed a carton of juice and put it in her sons meaty fists.

"Diddy darling, you just stay there a moment while Mummy brings out the bottles, OK?" Petunia said to Dudley. She stroked his hair lovingly, then went out into the hall and opened the front door.

She screamed and dropped the bottles.

There was a baby on the porch!

"Petunia?!" came Vernon's alarmed cry from upstairs. "What is it? What's happened?!"

"There's a - there's a - " Petunia gasped, panting for breath. "There's a baby on our doorstep!"

The baby's eyes opened wide, Petunia's cry having startled him awake. When Petunia saw those eyes, she gasped - the eyes were beautiful, bright-green and almond-shaped. Lily's eyes.

"Harry?!" Petunia hissed, scooping her supposed nephew up into her arms. She had recieved a letter and picture of the boy from Lily and Potter when he was born, but she'd never seen him in person.

Vernon thundered down the stairs. "Did you say something about a baby?!" he said, alarmed. He then spotted the blanketed baby in Petunia's arms and let out a cry of shock. "Wha - Whose baby is that?!"

"Ma!" cried the baby suddenly, startling Petunia and Vernon. "Where Ma? Where Da?"

"There's a letter!" Petunia said as she noticed an envelope clutched in the boy's tiny fist. She removed the letter from his hand and pushed him into Vernon's arms. "Vernon, you take him."

Petunia went into the kitchen and sat down beside Dudley, for once ignoring his yells of, "MA! BREKKY, NOW!"

She looked at the thin, slanting handwriting on the front of the envelope. It had been twelve years since she'd last seen it, but she could remember it like it was yesterday. Sighing, she slit the envelope open and pulled out the letter.

Dear Mr and Mrs Dursley, it read,

I am afraid I am the bearer of bad news - Lily and James Potter are dead. They were murdered by the Dark Wizard, Lord Voldemort. Only their son, Harry, survived - the mark on his forhead is where he was hit by the Killing Curse.

Harry survived because Lily put herself between him and Voldemort, thus creating a blood protection. If Harry stays here, with his blood relatives, he shall be protected from Voldemort, should he return.

For Harry's safety, and for your own, he must stay here. I hope that you will raise him as your own, but don't tell him too much about the Wizarding World right away - we don't want him overwhelmed.

Once Harry starts school at age eleven, I ask that he returns home at least once every year in order to preserve the protection spell, until he turns seventeen, when the charm shall cease to function.

Best wishes,

Albus Percival Wulfric Brian Dumbledore.

Petunia put the letter down, her hands shaking.

Her sister was dead, and she was left with her baby.

"Petunia?" Vernon called, bringing his wife back to her senses. She shook her head and went out into the hall to meet Vernon.

"Well?" he asked. "Whose baby is this?"

"He's Lily and James's son," Petunia said quietly. "You know. My sister and her husband."

"But why is their baby here?!" Vernon exclaimed, looking down at the squirming Harry. "Unless . . . They're not - "

Petunia nodded slowly.

"Oh, Petunia," Vernon said awkwardly. "I'm so sorry." He knew that Petunia and her sister didn't talk much, but he also knew that Petunia still secretly adored Lily, and was surely devestated by her passing.

Petunia handed Vernon the note, and took her nephew from him while he read. She looked down at him and bit her lip. He was gorgeous - a cutely chubby face, with thick, messy black hair and her sister's beautiful green eyes. When she looked down at Harry James Potter, she never wanted to look away again.

"Well, one thing's for sure," Petunia thought fiercely, "I'm keeping this baby. For Lily."

Vernon finished the note and looked at Petunia. "What do we do?" he said. "Should we keep him?"

"Yes!" said Petunia. "Vernon, he's our nephew. We're not dumping him in an orphanage."

"Yes, but . . ." Vernon looked at Harry again before continuing, "Petunia, he's one of them! He's a . . . a freak!"

Upon hearing that word - the very same word that had ruined her relationship with Lily - Petunia slapped Vernon hard across the face.

"OUCH!" he bellowed. "Petunia, what the ruddy hell - "

"Don't call him a freak!" Petunia nearly screamed. "I am keeping him whether you like it or not, and if you have a problem with that, then you can get out and I'll raise him on my own!"

Vernon looked aghast. "Petunia, of course I won't get out. I love you and I love the babies. If you want to keep . . . Harry, then I'm fine with it."

Petunia smiled at her husband. "Thank you, Vernon," she said. "Now, we'd better introduce the cousins."

She brought Harry into the kitchen and placed him on the table top in front of Dudley.

"Dudley," she said slowly and clearly, "This is your cousin Harry. He's going to be staying with us from now on."

Dudley blinked up at his mother, then at his cousin. Petunia waited for his reaction with bated breath - Dudley wasn't very good with other children his age. But, to her surprise, Dudley's face split into a grin, and he waved a meaty hand at his cousin.

"'Ello!" he said to Harry. "Me Dudley!"

Harry blinked at Dudley, then whispered, "Hi,". It was clear that he was missing his parents - had he seen them die, or did he have any real idea of what was going on? Sighing sympathetically, Petunia scooped the infants up into her arms and brought them into the living room.

Petunia placed the boys on the rug and gave them some toys to play with. As they played, she sank down onto the sofa and allowed the thoughts to process.

"Oh, Lily," Petunia thought, "Why didn't you tell me you were in danger? I could have helped you . . . Lily . . ."

She thought back to a time when life was sweet . . . when her and Lily were still the best of friends.

"Lily!" Petunia Evans giggled, running after her younger sister. "Come back here!"

"Can't catch me!" cried the seven year old. "You're too slow, Tuney! You're too slow!"

"This isn't how you play hide and seek!" said Petunia. "You're supposed to let me catch you!"

"You're just jealous because you're too slow!" exclaimed Lily, looking at her sister over her shoulder as she ran to a tree and began to climb upwards. "Can't catch - AAAAAAAAHHHHH!"

The branch under Lily's feet had broken. Petunia gasped and ran to the tree as Lily fell, but to her shock, Lily was suddenly suspended in mid-air.

"Tuney!" Lily screamed. "What's happening?!"

But Petunia could only watch in amazement as her little sister began to float gracefully down to the ground.

It was the first time Lily Evans discovered magic, and it proved to be the wedge that drove her and her sister apart.

"Lily . . ." Petunia whispered as a tear rolled down her cheek. She had lost her sister, and she hadn't even gotten a chance to tell her she was sorry. Well, she wasn't going to make the same mistake with Harry. She was going to raise him like he was her own son.

Seven years later...

It had been nearly seven years since that day, and on the morning of June 8th, 1988, Petunia was helping her daughter get ready for her seventh birthday party.

Dana Dursley was a bright, happy child, who was rarely seen without a smile on her face. She had her father's thick dark hair and her mother's thin figure and large, pale blue eyes. Her nose was slightly crooked (it had broken when she was five, after she fell off the kitchen table), she had a face full of freckles and a gap in her teeth. She wasn't especially pretty, but you still couldn't help but smile when you saw this cheery little girl.

"I can't wait for my party later, Mummy!" she said excitedly as Petunia brushed her hair. "My friends and I have been looking forward to it all week!"

Petunia chuckled softly as she tied the girl's hair up with a pink ribbon. "I hope you have a lot of fun, darling. Now, let me just get your party frock for you."

Dana's face fell. "Mum, can't I wear something else?" she grumbled. "I hate pink. Can't I wear a yellow dress instead?"

'Dana, you don't have a yellow dress,' said Petunia as she went to open Dana's wardrobe. Just before she opened it, she heard Dana muttering "Yes I do,".

Petunia gave an audible gasp as she opened the wardrobe; every single item of clothing in it was yellow. Before her very eyes, the clothes began to change colour; orange, purple, green, blue, red, black, white. Every colour except pink. As the clothes turned yellow again, she heard Dana giggling behind her.

"See, Mummy!" said Dana. "I do have a yellow dress!"

Petunia fainted.

When Petunia came to, she found Vernon, Dudley, Harry and Dana kneeling beside her.

"Petunia!" said Vernon in alarm. "Are you all right, sweetheart?"

Petunia sat up suddenly, gasping for breath, and pointed at Dana incredulously.

"Dana!" she gasped. "Dana - she - clothes - wardrobe - witch - colours - "

"Mum, you're not making any sense!" said Harry. "What's going on?"

"It's my fault," said Dana in shame. "I was just making my clothes change colour, and I frightened Mum, and she - "

"Wait," said Dudley. "Did you say you made your clothes change colour?"

"Y-yes," said Dana nervously. "Is that bad?"

"H-how?" stammered Vernon, thunderstruck. "How did you do it?"

"I don't know," said Dana. "I was just thinking about how much I hate that pink dress, and thinking how I wanted it to change colour, any colour at all - and next thing I know, all my wardrobe is changing colour."

Petunia could only say one thing to this.

"Find me an owl," she said hoarsley. "The party is cancelled. I need to talk to Albus Dumbledore right away."