Flawless (Working title)

I love how I already have a great sense of what the characters are like, that's a sign of a great writer, but with so much of what you've written pointing in the direction of what the characters are like, I'd love to hear what they look like. Maybe it would be a good idea to insert a few descriptive bits in there during the opening scene with Hanna and her friends.

Hey KitxKat! Nice work.

Here are my comments for you:

~Overall, I like the story. You pull the reader in right away, and the plot you've set up has a lot of potential.

~The grammar needs some attention. Also, you should (generally) keep to one tense (although I do agree with SporkPunk up there ^^^ that the tense change from the first part to the second is actually pretty effective). Since these things have already been pointed out to you, I won't go into detail. Just think: commas, commas, commas! :]

~I agree with SporkPunk that you need a different reason or a better build up to the discovery that the protagonist is bulimic. You hint at it early on, with the mention of the pizza, but the transition from finding out her parents are getting divorced to making herself throw up is rather abrupt.

~“You’re mother and I are getting a divorce.” Okay, this is one that the first reviewer missed. You've used the wrong word here. "You're" is a contraction, as you probably know, and is short for "you are". In this case, you should use "your", which is the possessive form of the word.

~Try and be aware of your character's voice. Words like "totally" (as in, "My grandparents on either side are totally anti-divorce.") make it a lot more casual. That's fine if that is what you are going for, but just pay attention. Consider what you want the narrative parts to sound like. This should have an impact on your word choice.

~"They are at it again. I can hear my momma’s sweet voice raised with frustration. My parents are locked in one of their heated, impossible battles." Fantastic. I can see flashes of wonderful narrative in your writing! You've got a few very revealing, powerful sentences here.

Hi KitxKat! I'm SporkPunk, and I'll be reviewing this today.

Green is for word choice change, red is for grammar, and blue is my commentary.

It’s amazing what girls will do to be perfect. Even as a daydream. I don't exactly understand this significance of this line. It's a little awkward. It was during lunch, and Lisa, Jamie, Courtney and I were looking through the latest Seventeen and Teen Vouge. Magazine titles need to be italicized when directly referring to them.

“Look at how thin these models are!” Lisa said. Lisa was an idiot, but she was a great dancer, so nobody truly cared about her GPA. Okay, so for this part, you switch tenses. You should pick one tense and stick with it. If you use present, make sure it's for an actual reason, like the story requires a sense of urgency.

“Yes,” I said, “airbrushing, much?” Courtney eyed one of the models in Seventeen.

“Have you ever thought that you’d be prettier if you were thinner, Hanna?” Courtney asked. She glared at me with her brown eyes. I automatically let my hand fly to my stomach, regretting the couple of slices of pizza I just had for lunch. I pushed the plate away. I really hated Courtney. She wasa total bitch.

Spacing is a good idea.

“That’s what I thought,” she said coolly, standing up and grabbing her messenger bag, “here’s my plan, ladies. Five weeks, ten pounds per week. By October, I will be fifty pounds lighter.”

“I’ve been meaning to do that too!” Lisa said. I stared at Courtney.

“That’s crazy,” I said, “you couldn’t drop that much weight in five weeks.” Courtney rolled her eyes and crossed her arms.

“Why, you couldn’t drop that much weight.” She mimicked in her annoyingly perfect imitation of my Atlanta accent. I grabbed my backpack.

“You know, losing some weight would help me on the field,” Jamie said. She is really sporty. We’re on the schools field hockey team together.

“Jamie!” I said, “you don’t need to lose weight.” Courtney smiled and looked at Jamie and Lisa.

“Are you with me?” she asked. They both nodded, but hesitantly. Courtney giggled.
“Perfect,” she said and turned to me, “we’ll see you later.”

It isn’t a friendly goodbye, it’s a dismissal. I have no clue what I’m going to do.

For this part, I won't correct the tense because I think it works. I put everything in past up there because that was the first tense you used. : ) I've seen a few books where the author will sometimes switch tenses in different parts of the book.
They are at it again. I can hear my momma’s sweet voice raised with frustration. My parents are locked in one of their heated, impossible battles.
“Hanna!” My momma calls. I remain sitting on my bed. There is no way in any hell that I’m going down there.
“HANNA!” My daddy roars. I get up and dash down stairs. Nobody wants to cross Daddy when he’s angry. Since "Daddy" is the name she calls him, it should be capitalized like any other name.
I arrive in the kitchen, and stare at my parents.
“Yes, daddy?” I ask, trying to be sweet. I notice tears running down my momma’s cheeks. This is very bad.
“You’re mother and I are getting a divorce.” Daddy says. I stare at them. My grandparents on either side are totally anti-divorce. This is completely unrealistic. If parents are going through a divorce, they wouldn't really inform their child heatedly, fresh from an argument. They'd normally wait until they were calmed, and explain it delicately to the child and not inform them of the reason right off...like below.
“Because he’s a cheater!” my momma said, “out of the almost-thirty years we’ve been married, he decides he wants a whole other family.” I don't think parents would divulge that information to a child.I stare at him. This is my daddy. We are best friends.
“Another family?” I ask. Daddy shakes his head.
“Hanna, I’m moving out. You’re mother and I are getting a divorce.” I shake my head.
“No!” I say, “no, Daddy!” He’s already brushing past me, and up the stairs. He’s not listening to me.
I do the only thing I think of. I race up to my bathroom, slide in front of the toilet and force myself to throw up everything I had eaten. I don't really see this as realistic, and it's a bit sudden. Something more realistic would be to make her throw up because she thinks somehow the end of their marriage is her fault, and one of the few ways she can take control is to do that. Just a suggestion. : )