It's such a hard one. I would probably sit down with the family and explain to them that although you appreciate their situation the late pick ups are draining on your family time and see if you can come to a solution together. Maybe they dont' realize the effect it's having on you. Sometimes when I'm under incredible stress you forget little things... like how your actions are effecting other people... they may not realize.

I don't think I'd go to late payment right away. They have a lot on their plate. If they need the late pick up then let them know it's an optiong (if you're even willing to do it ) however you have to charge a little extra to make it worth your time.

I don't charge late fees. My time is my time. If they aren't here on time we have a discussion and it doesn't happen again un nessasarily. No amount of money will make it ok for someone to take away from my family time.