From the outside looking in.

Thanx guys! I really appreciate the help and tips . I'll fix it and play around a bit more..
Im so glad I've found this site. My confidence in what I write has shot to an all time high..

It’s a lovely piece and the twist in the end is very good but there is one thing that confused me. Who is I?
The words, “I was the epitome of her existence.” Seemed to tell that I is the ballroom. That would make it an interesting story of having a story based on the perspective of a ballroom. However at the end, the I seemed to take on a personal figure and a person. This seemed confusing. The nature of the “I” is daunting and it changes.
Firstly, we got the ballroom I, the creature I (I silently watched in the high ceilinged corridor, I would quietly laugh with her.) and the personal I. What is really going on here? It feels a little confuse unless you are trying to suggest that the “I” are all these natures combined.
Other than that, the characters are interesting and the description you had given us able to let us see on a bigger picture.

Hey there! I'm here to review your story.

It's a beautiful little piece you have here. your descriptions in the second paragraph are wonderful; you have some great similes, and I could almost feel the power, grace and motion that she's got when she dances.

Like Gryphon said, there were a few things I noticed grammar/spelling wise...

PandorasChild wrote:She was here every day, Perfecting. Were you capitalizing this on purpose? Pushing harder, to reach higher than she already was. She, in herself, was an art-form.
Ballet was the reason air filled Alexandria’s lungs every day. I was the epitomy spelled "epitome". of her existence. Grace wrapped itself around her and seemed to make her stronger but lighter, faster but precise. Even when just practicingcomma people couldn’t stop themselves from staring. Their wide eyes watching, expecting her to span a pair of wings and fly away, or evaporate into a ray of sunlight that crept in through the old windows, for someone could only imagine something so beautiful. She never noticed the small crowds of gathering people that gazed and gawped outside of the studios window. Or maybe she did. When the sun set and the light switch along with it, she seemed to ignite a light within herself. Her movements became louder and less controlled. Her powerful legs now threw her into the air instead of just holding her up. Her breathing became deep, her entire torso expanding and contracting. She was a mass of strength and power, no longer delicate. She would start gently, growing increasingly sharp and jagged. Like a crescendo in music, she would raise elevate faster, stronger, deeper, until suddenly she would collapse. She lies This switches tenses; you've been describing her in the past tense, and now you're telling us what she's doing in the present tense. in silence, a silence that would be followed by either sobbing or laughter and as I silently watched in the high ceilinged corridor, I would quietly laugh with her.
To dance with a force like that, would’ve killed me I’m sure. To try and be a frame for a masterpiece such as her, I simply wouldn’t do. No, she danced with no man. She didn’t need one. Everyone knew that. Just watching her was already a privilege
One day, walking past the studio she normally inhabited, I found it empty. The only dancing being done was by flecks of dust in the ray of sunshine that belonged to Alexandria. I love this wording! It felt eerie. Something was wrong. I waited until that night to return. The studio was dark and cold. Religiously, I did this every night hoping and praying that she had returned.
She was at the height of her career. No one knew why she was still attending Julliard when she could be dancing as a prima ballerina in Russia. Apparently they were recruiting, maybe she had left. My chest twinged at the thought. I didn’t ask anyone about where she might be, too afraid that my face would give away my concern ... an illegal concern. I, however, still checked every night.
Six months later, I found myself stretched, forced to endure. She had still not come back.
I considered asking her friends, but I couldn’t think of any she had. Time practising left none for friends, rather acquaintances. And besides, I still didn’t trust in my ability to act nonchalant...
One evening, while the rain dropped to the ground, I crept in through the men’s bathroom window, the window I’d squeezed through for most of my studying years. I walked casually down the corridor not expecting her to be here. I was grateful that the older studios didn’t accommodate alarm systems.
I had almost started whistling as I strolled into her studio, but stopped in my tracks as I walked through the large oak doorway.
An old lady sat in a wheelchair, staring at herself in the mirrors. With the moonlight provided from the large windows, I could make out her faint outline. Her bent legs were folded in a blanket and a cardigan donned her shoulders.
“Excuse me, ma’m. Are you lost?” I asked, wondering how she had found her way in here.
“No,” she said after she had shot her head around. She wasn’t an old lay at all. Her wet cheeks, smothered in tears, shone in the blue moonlight. Those cheeks, that nose, the rose coloured, pouting lips...
“Just paralyzed.” Alexandria cried.I don't know whether you intended this to be where she says that she's paralyzed and then she cries, or if she cries "Just paralyzed." If it's the former, maybe you could make it into a different paragraph, just to clear it up. If it's the latter, I think a comma would suffice.

*sniff*

The description in here is beautiful. The second paragraph especially was amazing.

Main thing I noticed was a bunch of little typos.

I was the epitomy of her existence.

Their wide eyes watching, expecting her to span a pair of wings