Fire And Ice - Yin and Yang (Harry Potter fanfiction)

The boogey man

On their first day, the twins practically leapt out of bed at six thirty a.m because they were so excited.
Lavender and Parvati were still sleeping, but Hermione was awake as well. Together, the three of them quietly got ready in the bathroom, having some trouble to put on their ties correctly.
The twins decided to keep wearing their fingerless gloves. They didn't want anyone staring at their hands.

"Look at my hair", complained Hermione and stared at her reflection. "It's so- urgh."

"It's lovely", said Periwinkle, "I bet if you'll let your hair grow, you'll have nice waves."

Hermione shrugged unsurely.

"Here", said Azalea and pressed a spray into Hermione's hand. "Our curls would look even worse if we wouldn't have that. It's some kind of hair thing that straightens our curls a little."

Hermione inspected the bottle, then decided that her hair could only get worse, and pressed down the spray button. Fifteen minutes later, the three were on their way to breakfast, still coughing from the cloud of spray that Hermione had released into the bathroom.

"I didn't know the stuff would practically shoot out of the can", Hermione defended herself.

Periwinkle snorted in laughter.
"At least our bed hair looks more acceptable now."

"If you'd have black hair", said Azalea to Hermione, "we could be sisters."

Hermione turned pink.
"I wish I had sisters", she mumbled.

Periwinkle and Azalea traded a look. Then they each hooked an arm around Hermione and pulled her towards the Great Hall. Together, they chose to sit at the end of the Gryffindor table near the High Table.

"I think we'll get our timetables soon", said Hermione hopefully and grabbed herself some toast. "I do hope we have Transfigurations today, it seems so interesting."

"Do you think the lessons will be hard?", asked Periwinkle, sounding slightly worried. "I mean, I've never really done magic with a wand before."

"Percy said we'll start in Transfigurations with small objects", Hermione replied, her eyes twinkling excitedly. "But I can't wait to move on to real animals."

Slowly, the Great Hall started to fill up. More and more students trudged into the hall, the first years looking quite sleepy after staying up all night from excitement.  At some point, Hermione left to ask Percy another question, who was sitting at the other end of the table, while the twins finished their breakfast.
The Heads of the Houses started distributing the time tables, as Hermione had predicted, and soon, Professor McGonagall appeared beside Azalea, holding two parchment scrolls.

"Your time table", the Professor said and handed a scroll to Azalea. The girl immediately opened it and found her name to be on the top.

How did she know I was Azalea and not Periwinkle?, she thought surprised.

Periwinkle got a scroll too, staring curiously at Professor McGonagall.

"Is something the matter, Miss Potter?", asked the older witch stiffly.

Periwinkle flinched, as if she hadn't been aware that she was staring.
"No, professor, sorry, it's just- er-"
She glanced at Azalea, then stammered to Professor McGonagall: "Have we met before?"

Azalea looked up at the professor, who was examining Periwinkle with an unreadable expression.
"Yes", she said finally. "When you two were about four, you somehow managed to sneak onto the Hogwarts Express. A friend of the headmaster brought you here, before you returned back to your relatives."