How do you find a lost pen pal?

That is my challenge at the moment. We wrote back and forth for 8 years and now it has been just about a year since I've heard from her last. I've written a few times to the last address I have... and yet no response.

Sadly the beauty of this pen and paper relationship may now cause its end. We never exchanged any other contact information.

Our correspondence started in my 6th grade class. It was an assignment... our class wrote to this a class in Finland... I don't know how we were paired up, but at the time it really didn't matter we only wrote back and forth a few times.... I left the elementary school and forgot about my pen pal. Two years later around my birthday, an odd looking letter addressed to me came in the mail. I thought it was another chain letter.... to my surprise it was my long lost pen pal from sixth grade, asking if I would like to rekindle our friendship. We began a regular dialog in care of the post office. Some times months passed, sometimes only weeks passed, but never years…

The other day I expressed my dismay to my mom... her words were something along the line as people move on...

I know I'm very guilty of letting other relationships die... this one however; I really want to put up a fight for.

This leaves me back where I started.... How do you find a lost pen pal?