Ok, I am not saying this is a bad thing...actually this is my most favorite chapter of all of your work so far...but I have seen some error that I am going to explain what and why to help you out.
"Oh my gosh!" she said, "This is so cool! You'll be moving up soon, I guarantee it!"
(The hole, she said is not important to say as the reader allready knows who is talking)
"I don't know," Christine said, looking over her shoulder at another girl that was at another mirror. The girl was doing her makeup, a frown on her face. She had long, silky blonde hair and was about the same age as Christine. "I doubt she'd let me be a trapeze artist."
(Christine said, looking ...could be easier as just ...She looked over her shoulder....As yet again we allready knew who was talking)
"Oh," Melinda said, glaring at the girl, "Victoria. Gosh, that girl annoys me. She thinks she so cool because she's been doing the trapeze for forever."
(She thinks she so.......should be She thinks she's so.........or She thinks she is so)
"Don't listen to her," Melinda said, "She just thinks she's the queen bee. Curtis has the last say in everything, and if he knows you like I do, he'll let you do it."
(Melinda said...in the middle is unnescesary, we know who is talking so we don't need the split up in the middle of the sentance)
"Shouldn't you be working on yours?" Christine asked, "Normally it takes you twice as long for you to put yours on than it does mine."
(Yet again, Christine asked is not needed...."Normally it takes you twice as long for you...." Should be something more like. "Normally it takes you twice as long as it does for me." It lets the sentance flow a little smoother)
The two girls headed outside of the tent. Melinda walked towards her trailer, and Christine towards her and Glenda's. They still had yet to get into their costumes for the show, and their dress rehearsal was in an hour.
(They still had yet... Should just be....They still had to get... The whole 'yet to', makes it almost sound as if you are dubbling the sentance structure)
"Okay," she said, running off to her trailer.
(She said, running... Would sound better as: "Okay." She went running off to her trailer.)
Kyle looked up at her and started making his way towards her. A ray shot down from the sky and hit Christine, sending her flying off of the platform. Christine felt the ray shoot through her, and she cried out in pain. White streaks appeared in her hair from the high amount of heat, and her eyes turned almost completely white. She looked around her and squinted. She felt herself stop falling, and she looked below her. She was about foot off of the ground, and she was floating in the air. Christine looked below her in surprise and dropped herself to the ground. She landed on the floor, and her eyes turned back to their normal color.
(She was about foot....is missing the a before foot........The first part of this sentance repeats her....he looked up at her and ran towards her....try not to repeat a word, it makes the sentance sound more like droning than story telling)
Matt stood in the middle of the crowd, looking up at the sky. He looked down at his palms. The lightning bolts were still in the middle of his palms.
(Palms was reapeted here...try to keep that down....use: He looked down, the lightning bolts were still in the middle of his palms. for example.....it makes the sentance seem shorter and more fluent)
The whole she said, he said, bob said can mostly get left out as the reader can mostly tell who is talking (I had the same problem myself) and once you leave it out, the story seems to get shorter, but in a good way
Overall this is one hell of a good story and I cannot wait to see more and more of this stories development
so keep updating
P.S. (I hope my words have helped you and not made you think less of your writing, I am merely trying to help you make the best of your allready good work)