Good stories come from the main character's voice and thoughts NOT from the writer.
Here are a few things you can do to find out who your character really is and to get them talking.
Start with an interview.
Not the kind where you've got a list of questions you want answered. Just sit down with your character as though they're a stranger on the bus. Just chat. Ask them about the Spiderman tattoo on their arm. Or start with something simple, ask where they're headed. Let them talk. Don't force anything, and don't be too intrusive.
If your character doesn't want to talk to you, then approach her in a different way. Maybe your character will talk to her grandmother. Or her best friend. Or her stuffed animal. Maybe she'll talk to herself in the mirror, and you can hide out in the bathtub behind the curtain listening in and jotting down notes. (Does that sound creepy?) Do what you have to do to write your story. But get it from your character's point of view. Nobody wants to listen to you tell as story about some character.
Sometimes our characters have things that are none of our business. And maybe they'll tell us that. Just let is slip. If you want to know something and they aren't talking, then move on. Get the story that they do want to tell.
Keep writing :)