I fell in love with a girl i have known at least 9 years, (or i am just noticing that i am in love with her), and i [need] a quote to tell her, as i haven't done so yet.

a commonly used quote: "I love you!!"

I posted a very similar thing, they told me to tell him that 55% of people fall in love with their best friends, then kinda joke about it, say..."Damn I hate being another statistic" Keep it light in case it shocks the other person. Give them a chance to adjust to it. It worked out very well with me and my best friend, he actually told me he loved me, so I hope things go well...good luck. Or you could also say...I fanned the sparks of friendship and they fired into the flames of love.