I don't do a discount for siblings either, but I remember considering it in the beginning. I thought at the time that siblings would be better because when they go on vacation, 2 kids would be gone instead of one, when they leave for the day, 2 kids gone again, and (where I was really dillusional), I thought that if one was home sick, they would both stay home. Boy was I wrong! I have siblings (thank goodness I didn't offer a discount) who are always here...if one is sick, the other comes...if one has an appointment, the other is here, the parents take vacation days without the kids and they are the first to arrive and last to leave! The only time they are away is when I am closed for my vacation or occasionally they do take a family holiday and they are both gone. But definitely there is a risk that if they both leave the daycare, I have 2 spots to fill at once and I wouldn't really want to start 2 new kids at once.