Is it common for only one sibling to go to boarding school while the others go to day/public school?
I think it is fairly common. My oldest son attended prep school, my daughter applied, was accepted and decided to attend the LPS. Now my youngest is talking about applying. The point to take from this is that each kid is unique. The right boarding school for one may well be the wrong one for another, and boarding school may not be a good option at all.
Same here. One will start boarding school, another stays in public school.
Yes, I’m going to boarding school and my siblings are staying at public school. It’s perfectly fine, don’t worry 
I have two at home in public school and one heading to boarding school.
Yes - many families have figured out what works best for one kid is not the best for another child. Some kids at DS boarding school have sibs there but many have sibs in other schools - occasionally different boarding but many in public or local private.
Yes, it is common. Some kids need/want the boarding experience, while others wish to remain at home.
Boarding schools do seem to like having siblings on campus, so it can be a plus factor in admission for a suitable child. On the other hand, if the sibling is not a good fit for the school, boarding schools have no problem not accepting siblings.
At a day school, if the school doesn’t accept a sibling, the school might lose both (all) the children from that family. That’s rarely true for boarding students. I suppose they’re more likely to lose all the children from a family if a child who was a poor fit flunks out or fails to thrive.
So if you’re a sibling, if a boarding school accepts you, it means the admissions people believe you can make it through. On the other hand, it’s by no means a guarantee, and you should apply to more than one school.
I am about to drop off dd#2 at her new school and dropped off dd#1 this last weekend. Very different schools for very different daughters. It would be great for me if they went to the same school but they are simply so different and fit seems so important that we are just trying to surf the wave of good fortune that they are both where they want to be (with fabulous FA). #pinchingmyselfonaregularbasis
BS of sibling #1 was very attentive to the app. of #2 and gave helpful assistance on sleepover, etc. The BS turned out to be a good fit for both siblings, of which there are a good number at St. Andrew’s-DE. Perhaps more than most peers, SAS seems to really like to have “family connections”, and multi-generational at that.
I have read that there may be an issue with yield protection for siblings wanting to go to a different boarding school. For example, as soon as the Peddie AO finds out that a qualified sibling is applying to the same school her brother goes to, they automatically put them on the wait list. I think that this might be an issue for my daughter next year.
There may be some truth to that; however, if K2 really wants to attend a different school, that should be made crystal clear to the AO.
It’s not an issue if you’re open with the AO. All you need to say during the parent interview is- your child is very open and excited about exploring different schools ( beyond the sibling school ). The care and attention she gives to AO / Department Head/ Coach correspondence and the app will tell the non-sibling school everything else they need to know.
There are loads of people at my boarding school who talk about their siblings back home. Sometimes they’ll visit. It’s totally not a big deal.
It’s certainly very common for the sibling(s) to attend another school(s), whether boarding or day.