Heya Mia and welcome to HPRPG~!
However, before we can sort you, we're going to have to ask that you give us a bit more into her history and write it in paragraph form without the continued spacing between sentences. :3 We're looking for more about Mia, mind, so while the information about her seemingly neglectful parents and nanny are nice fillers, we still want the majority to be about how Mia grew up and how her childhood was.
Additionally, with the strengths and weaknesses, make those paragraphs as well. Perhaps even give us some why behind them? Why is she strong-willed, independent, ambitious, and a perfectionist? Why is the cold, and evil, and hard to handle? Do you think 'evil' might be too big a word for an eleven year old girl? ;3
Lastly, we need a reason why she belongs in Slytherin. You gave us a reason for Ravenclaw, but... well, we need one for the house you're chosing, too. <3
Once you've made the above changes just swap the title from 'pending' to 'edited'.