You really are over-thinking it, in my opinion. You're not friends, all you can do is ask. Or you can get her to like you again, pretend to be her friend, gently bring it up, get the $50 and then tell her you'll pick her up from the airport and then don't do it.
Or really, just anything mean in the end.
--
Digi
“They took out my left ventricle and atrium,” James said half-heatedly.