1) You put her hair is blue and she likes to change it alot - so is it blue right now? or blue for good? Cos she says its green pink later. If its blue for good then its confusing saying she changes it a lot.2) Why would she want to seem rude or mean? Since you said shes a nice friendly girl.
3) What does she try to hide? That she is brave or that she is afraid of heights?
4) How can she be too easily trusting sometimes? Surely that is either her personality or its not?
5) Her history seems mostly devoted to her life after starting Hogwarts - its meant to be all about her childhood and you give very little on that.
6) You say she really tries to be nice and kind like people say? So are you saying that first part isn't her real personality but just what people say about her?
7) You say she had too much freedom so she dyes her hair a lot. Is dying her hair really having too much freedom? Or does she have too much freedom and she does that.
London is not the country - England is the country, London is the city.