"How you responded to a significant challenge" UBC essay; Asperger's syndrome

For my UBC application I have to write the following essay
Explain how you responded to a significant challenge that you have encountered and what you learned in the process. (maximum 200 words)

When I was twelve years old, my sister was diagnosed with Asperger's syndrome. The diagnosis changed everything in my life; my family dynamic, my relationship with my sister, the way I treated other people and most of all the way I viewed the world. I'm three years younger than her, yet I had to take on the role of the older sister and in consequence I had to grow up faster than most of my peers. I had to fight for my sister, convince her that it was all right to be different than everyone else. I was only twelve at the time, and I didn't always know what the right thing to do was. I had to learn to see things through more mature eyes. Caring for my sister, I understood what it was like to be the underdog, to be different. At times I was too young to know how to act or how to protect her, but through all of this I grew as a person. It's never going to stop being a challenge for me, but she will always be the most important person in my life.

Please help me!

SofiAnabelle: You have written very good piece, make your sentences shorter. That will be easy to understand. I did some changes as beneath.

I was only twelve at the time, and always I didn't always know what the right thing to do?was .

I had to learn to seeing things through more mature eyes.

Caring for my sister, I understood what it was like to be the underdog. , to be different.

At that time I was too young to know how to act or how to protect her, but through all of this I grew as a person.

Your eassy is good for me. ^^
Your writing have great unity, suppose, and coherence. ^^