I don't think that I would personally ever do this as I need my "me" time when I can get it and it would greatly affect my relationship with my own kids who want their mom to themselves during the evenings and weekends. But if I ever did entertain the idea, it would only be with a child that I knew very well and who is likeable, well-behaved and not high maintenance. I would then treat the child almost as if she was one of my own. There wouldn't be any planned "daycare" type of activities during the evenings or weekends. There would a lot of down time where the child would be expected to play independently so that I can just sit and relax. There would be some TV watching. She would be going with me during the evenings or weekends to anywhere that I needed to go. And there would be times (which the parents would know about) where another family member may need to care for the child temporarily if there was something that I needed or wanted to do that didn't involve the child. Basically I wouldn't want it to feel like "work", but rather this child would be part of our everyday family activities. I'm not sure if this is realistic or how many parents would go for this, but it's the only way I could keep sane and not burn out quickly.