If you get on the ball (depending on the distance) you could mail a "pre-card" to get to her by Wednesday and she would get the chocolates Thursday or Friday from the manufacturer... of course that's all about timing...
You could just overwhelm her with cards and notes. Make her postal worker have a tough time putting them all in her mail box. Mail some to other places she'll be (work or something)...
You could get tickets for a local show for the next time you are planning on seeing her and mail one of them to her.
You could mail her IOU's or one of those self-made "coupon book" type things for next time you do get to visit each other.