I've never been near a foul ball, but one time I was in the first or second row in the outfield at Turner Field for pregame warmups. There was a little boy with a glove by the railing not far from me, trying for a ball. When they finished up, guy for the other team tossed it our way and it went right to me. I caught it, took in a good look at the ball, and gave it to the kid. Honestly the thought of keeping it never even crossed my mind.
That woman is just a bad person. No two ways about it.