I've never had a sitter (other than my mom). I think it is so great that you have your friends that are also your sitters. It's special when you know they love your girls as much as you do.
As a thank you, maybe make them a gift basket of things they like, individualize it, ya know? Since you know them so well, you could do that. Or maybe just get them a card and a gift certificate to a good restaurant in town..or movie tickets for a night out and YOU would sit for them. Just some thoughts off the top of my head
