Happens all of the time with mine, i have so many, but none of them seem upset that a sibling got something they did not. For all the issues I’ve had with my kids, (and I’ve had some doozies), that was not one of them. The older ones also got things that the younger ones did not.
I guess watching the reactions and tempering yours to best support them is the best way to go.
Friends of ours were put in a tailspin when their younger daughter, a top student with a great academic profile failed to get into Brown, where her older brother was going with not close to the same package in terms of class rank, test scores, ECs. The young woman was very upset, as she assumed taht the sibling legacy would be enough of a tip to get her in, not to mention she was a stronger applicant by all measures that anyone could see. It was a tough situation, since having an unhappy child hurts so much.