Other things to consider are how long your current situation will last and what path you are preparing for. How long will the children be in the same schools? When will the oldest move up to middle school or high school and away from the youngest? Will the start and stop times be different anyway? When it comes time to pick a high school, will the school choice for elementary limit the options? Some districts have "auto admit" to special programs for students that were in a program during elementary or middle school. So if they were in gifted or IB in middle school, they can be in gifted or IB in High School. This may be true for the Catholic High School as well (Catholic middle school=auto admit to Catholic High School). Will joining the EG school now enhance the chance that your child will be in an EG program in high school? Exploring the admissions criteria for high school may help decide what middle school and elementary will be best.
Sometimes siblings just don't belong in the same place or program. During the winter olympics our family discussed at length what it must have been like for the siblings of the athletes. Some, like Carly Gold, are in the same sport and compete with their siblings (Gracie Gold). Others are into completely different things. Age, interest, and ability should ideally inform the decisions for younger siblings as it does for the eldest. Clearly, compromise may be necessary, but it may be helpful to consider what choices you would make if this were the only or eldest child.
