Oh, I hate that when something that got to be a habit stops and then you have to explain to the other person and can't quite do it. She probably won't stop trying to engage you either or you'll still tense going near her house or having to go a different route, etc. Feeling held captive.

I would occasionally take "her" route but say "Hi" and keep going if she's out. I wouldn't have any extra cigarettes she can borrow or buy ("Sorry, all I have are mine" LOL) and try to be pleasant but not engaging. I'd be VERY preoccupied and not respond or I'd start talking about the most boring problem of my own I could think of :-)