You're not getting much input from anyone besides me. I'll give my vote and see if anyone else chimes in.

1. Call her: I'd vote this if this will in some way give you closure...either know she's truly done or explore if there is still hope for a relationship.

2. Send another card: Just impersonal pursuing.

3. Send another apology letter: Pursuing.

4. Leave her alone: This is okay also. She's received apology letters and cards, the next move should be hers. I only suggested #1 as a way to come out of the dark. If that doesn't work out...you might have an idea where you stand and it may help you in efforts to move forward.

In the end, it's not the years in your life that count. It's the life in your years.
Abraham Lincoln

It is hard to fail, but it is worse never to have tried to succeed.
Theodore Roosevelt