My advice? Don't do it. You said you're not 100% sure she's the one, and my motto in life is "if in doubt, DON'T." Ask her to move in and spend a year getting to REALLY know each other. And if at the end of the year, you can't see your life without her in it, then do it. Marriage isn't something to jump into simply because you love the person - people fall in and out of love very easily. You both gotta be really invested in it and a year just isn't alot of time. Its hard work, more than people realize...and its not something to rush into. And this coming from someone who has been married and has learned a thing or two about it :2 cents: