Very confusing mixed signals from the girl I'm dating?

Why I'm confused:

-She says she wants to get married to me eventually, but won't make things official between us despite dating for 9 months and says she loves me deeply
-She won't add me on facebook, I added her months ago, she still hasn't accepted my friend request
-She won't tell me important personal details about her despite knowing each other for 10 months
-She still hasn't introduced me to her friends or family, despite me introducing her to mine