Madoka is a girl who is confident in one fact: she wants to help people. She considers herself to be good at little else, but shows happiness and strength in doing what she can. Her strength comes from how much she cares for others, but she's also self sacrificing to a fault as well. In canon, it seems that she lacks in self confidence until she decides to become a magical girl, partly because she finds strength in knowing what she can do for others. Despite her flaws, she earnestly tries to get to know and understand the people around her. Though she can be seen as naïve, she really is just a typical eighth grader who ended up in a situation with more responsibility than she realized. Even so, she thrives when she realizes that there's more she can do than she initially thinks. While easily influenced by others, she'll also fight to do what she believes is right when push comes to shove.

I would be apping her from one of the timelines in the series before the one we see -- one where Homura meets her after she had become a magical girl already.