My sister helped me grow into the person I and because of that I will always admire her.
Missing a word in this sentence.
How long does the school recommend you make the essay? A page? Two? Use paragraphs. End the first paragraph with an intriguing sentence that conveys the main idea of the whole essay. Can you sum it up in a sentence at the end of the first paragraph?
I think this needs to be longer. Also, the main idea of this seems to be: My sister has always been there for me and taught me important lessons. This is not very interesting. It is too plain.
I don't mean to be critical. You wrote some excellent sentences and you have a nice way of explaining things. But I want you to think of a concept... an INSIGHT. Do you know what I mean? Think of an interesting idea that relates to your sister AND your intentions for the future. Intrigue the reader with a concept that is worth writing an essay about. This is more like something you would write on a greeting card.
I think you can look at what you wrote and take inspiration from it. Write about a great concept that shows how reflective and thoughtful you are. Let's see a new draft that is longer and focused on one great concept! :-)