This September.
We aren't that far apart in age, but I'm a junior in college and she's still in high school, so we're kinda in different worlds at the moment.
Also, people younger than me often turn out to be super annoying... meaning this is the first time I've liked anyone younger than me.
She isn't a typical 17 year old, though... she's really smart, and she might be more mature than I am.
So she graduates next year, I imagine?
I have to agree with Cody, in that, this definitely isn't something you can rush into.
People change -alot- after highschool. I witnessed so many close friends and their friends do complete 360s in their life goals, dreams, habbits, etc. Sometimes for good, often times not..
I think, if you are truly serious about her, get to know her slowly, just as friends. I know - friend zone sucks, but despite assumptions can be beneficial. If she cares for you, she wants your friendship above all else.
But, this path is only if you are -truly- serious about this. Patience is your card here. Watch how she unfolds as the real world begins to settle in her mind after school. Be the guiding words and wisdom she needs to become the woman you want. You may think she is mature, but she may lack the experience you have when real-world stress becomes an issue.
She will either become someone you can't be around, or prove that your patience was worth it. I think the key is maturity, not age, so ensure she keeps that mindset.
That is my opinion-based input, anyway. From experience of knowing what I would have needed at her age, in that circumstance.
I will keep you in my prayers, bud!