I like communications. That is, talk a bit.
"Annie, I love how we're good friends. I was wondering, though ...."
Otherwise, you're left wondering what if, and you're repressing your true feelings in the matter. At least you know she's open to it! We see lots of folks who come through here who aren't even sure of that, which is a pretty fundamental thing, I'd say. You are WAAAAAAAAAYYYYYYYYYY ahead of the game.
Will it ruin the friendship? That is not outside the realm of possibility, so brace yourself as it could happen. At the same time, either something wonderful could happen or she is at least the good friend to you that she has been all along and lets you down gently.
Nothing ventured, nothing gained.