To see a girl in your dream represents your playful, innocent, and childlike nature. Perhaps you are behaving immaturely in some situation. Alternatively, a girl represents the feminine qualities of your character.
To dream about a girl that you just met represents your anxieties and thoughts of whether you had made a good impression on her and what she thought of you. If she told you that she disliked you in the dream, then it may be an excuse for you to dismiss her and not pursue a relationship further.
Dreaming that a little girl is trying to kill you represents an aspect of yourself that does not want to grow up. You are dealing with too much responsibilities.