Would this be sweet, or creepy of me to do?

So a friend of mine recently moved outta state. We're ONLY friends, nothing more. Although she did tell me she used to have a crush on me and I liked her too. Her sister still lives near me. So this girl is really into Koala bears, and I found a stuffed animal koala bear online that you can personalize the t shirt it wears. So as a surprise I want to order the bear, write on the t shirt "Miss you <3" and send it to her in the mail. The thing that would be creepy is I don't have her address, so I'd ask her sister for it (i want it to be a surprise). Do you guys think I should even bother or is it too over the top. This girl is really pretty and nice, guys all over her all the time, hitting on her. What do you think