Sounds like you may both be caught up in a game. She pesters you, you refuse, she stops/is upset, you want to repair the relationship? I think it would be best for both of you if you just saw her as someone leaving work that you used to know...let it go.
Treat her as you would any coworker (I hope) with respect when/if interactions are necessary, otherwise, since you do not work together, don't interact---if she talks to you, take it with some humor, and a grain of salt---be neutral, don't get emotionally involved/take it somewhere else----you don't have to be friends or enemies. (sorry, I hear myself lecturing...)