This is a question that has plagued DC area parents for decades. Hence the huge sigh of relief when they all (if there’s more than one) get into the same school.
Most schools have before care that helps with drop off. I know some parents have a “deal” with the school that in order to attend their DC will be late each day. For younger kids the early morning is usually free play/choice time before they have some sort of morning meeting. For middle school you’d have to check as most of them have the prime subjects first thing.
Depending on where you live, carpooling is always a great solution too.