Summarize:

It's hard to get to know someone well in a group. If you want to deepen your bond, spend time alone together. Go somewhere you can have a quiet talk, like a coffee shop or a restaurant in the middle of the day.  If you go to school together, just finding a quiet place to sit, away from other students, can be a great way to have a private conversation. It doesn't have to be a "date," and calling it one can put a lot more pressure on things. Just find an excuse to hang out together and talk. Eventually, your conversation needs to deepen beyond talk of school and bands and movies, if you want to get to know someone better. Ask about her opinions on serious issues. Find about what she thinks about. Talk the real talk.  Stay informed about world events and politics. Ask about her opinions regarding recent elections, or talking points. Find out what she cares about. Ask about her anxieties and fears. What kind of a person is she? What keeps her up at night? What does she want to do with her life? Where does she want to be in ten years? What makes her happy? These are important questions that will be good to talk about down the road, if you want to get to know someone.  If you're in school together, talk about your future in school. Is she hoping to go to college? What will she study? What does she want to be beyond school? If you're beyond school, talk about where you'd like to progress in life? Where do you want to live? Are you satisfied in your job? Do you want a family? Kids? Your job isn't to impress a girl, or "wow" her with your accomplishments. Your job is to be real if you want to get to know someone. Be yourself. Conversation is a give and take. Share deeper feelings and anxieties that you have, if you want to her learn about hers. Open up and put yourself out there.  It's possible to go too far with all the questions and come off as kind of a creep. If you never bring anything to the table, but want to know whether or not she wants kids, it won't seem like a conversation. It'll seem like an interrogation. You've got to talk about things, too. Let her ask questions as well, but don't wait for her too. You should both be sharing about an equal amount. But if she wants to talk more, let her. Seeing how someone interacts with their family can be a very telling experience. If you want to really see what someone is like, see how they interact with their parents. See how they treat their brothers and sisters. See how their family gets along.  This might take a while, but if you've been hanging out with someone a lot, coming over for dinner, or a quick hang-out is pretty common. Let her ask you first, don't invite yourself over. Introduce yourself to her family, and see how they react to you as well. Learning about someone's parents can be just as revealing as learning about someone.
Spend some time together one-on-one. Ask more complicated questions. Talk about the future. Open yourself up, as well. Get to know her family.