I really love my friends older sister; should i tell her?

I know that sounds really dramatic, but i really do feel like im in love with my friends sister; i only see her when im in his house. she's 19 and i'm 14 - i know that sounds really much, but i'm mature for my age i think. she's the most beautiful person i've ever seen, i really mean that, and she's a really friendly person. i was sitting in my friends front room the other day, he was in the kitcen and she was fixing her make-up or something in the mirror and she turned and said "ok how do i took?" and i just blurted out "really beautiful, you always look beautiful all the time" (i get nervous around her which im trying to work on) and she smiled and said "thanks kiddo, the war paint works wonders huh? i'll cya later" i think she was talking about her make-up. i know this sounds weird and all but i think about her all the time, i think i have a big crush on her, i know not everyone my age gets crushes on girls her age, but she has everything and its getting harder not to just say something to her. is it worth the risk??? how can i approach her and say something to her?! how do you even word it with a girl her age?! any advise is appreciated!