Do you think the fact that an older sibling was accepted to a school but chose to attend a different school will hurt younger sibling if he applies to the same school? I tend to think it might not matter at a large school but what about a small LAC that puts a lot of weight on demonstrated interest?
It shouldn’t make a difference.
Absolutely not. AOs are all adults and are not going to sulk if an applicant decides to go elsewhere. They all recognize that each child within a family has his/her unique reasons for selecting a college.