Whenver I am faced with one of those dilemmas...I always ask myself..what if that was my wallet and all the money I had in the world.
I would turn it in----in fact I found $20 bucks in a work bathroom once and turned it into the supervisor letting them know which stall it was in so they could properly find its owner. Sure enough they did and she found me later and thanked me. It did indeed happen to be her last $20 and she needed it for gas.
I didn't think that any person would even have to ask the question. It should be soo very obvious.
Shame on that "sister"
Spice