Well the truth in the situation is that i no longer feel the success of a relationship is measured by how long you've dated or courted. Someone you "get to know" for a year could still turn into the devil's incarnate after you've said "i do" and someone you've known for three months might retain their goodness . . and vice versa.
The advice you need, is in your heart. You alone know what and how you feel about this girl, is she someone you could imagine spending the rest of your life with, do you feel you're compartible, would you want her as a wife, . . these among others are questions you should ask yourself. If on the other hand you don't feel you're ready to commit, if you have some reservations about her, things about her you feel you still have to know . . sit her down and tell her you need more time, you're not yet emotionally ready to start courting . . and if at the end of the day you can't see both of you in a joint future, let her free before she develops deeper feelings for you.
You have the yam and the knife in your hands

Just remember marriage is a "life-time-contract", not something to rush into "just because" . . . !