I don't currently have any siblings at my daycare but when and if the time should come I am not planning on offering any type of discount.

I have two children in my daycare and each of them have parents who are teachers. The first year they were in my care I offered a special deal in that for the months of July and August I would only charge them $25 day for the days they didn't come and then would charge them the regular fee on the days that they did attend. During the second year of care I no longer offered this same sort of deal -as a family we just couldn't afford to take the reduced payments any longer. I have seen all sorts of different arrangements for the summer months with teachers kids. Some have the whole summer off for free, others charge a $200 a month holding fee for the child's space, others don't offer any discount at all. I think that you just have to do what is right for you and your family.