Mate, don't say that. (EDIT: referring to Shade's post, not la petite moi
)
If you've just met this girl recently, and she's a friend of a friend (which makes you a friend of a friend), then saying anything remotely like that is going to set alarm bells off in her head. It's romantic to you, but to have someone you've just met say things like that is going to scare anyone away.
Treat her like any other woman you'd like to date. Ask her out before you fall into that 'friend' zone, just ask her on a regular date. If she says yes then that's when you gradually let her know you're interested. Don't ask her to marry you, ask her to dinner.