Are you nuts?!? You're planning on sending a crayon drawing through the mail to propose? Like opening an envelope is supposed to be romantic? This is the moment you want her to remember for the rest of her life? I'm not exactly an incurable romantic myself (did you see the valentine's day post?) but even I can see, dude, this fizzles. I implore you, rethink this strategy. Okay, you know her better than I; maybe... she might be into... she may be desperate enough that... Dude, think of something else. Please.
When you are getting ready to go over seas and can't go home, trust me, it'll do wonders.