Alaska, 1927 proposal
Benny Benson, thirteen-year-old designer of the Alaska state flag, was only one of several schoolchildren that entered the contest. This cute little flag was proposed by one Mary Walsh, also thirteen. (I’ve digitized and cleaned up the original hand-drawn entry, but all the elements are in the same place.)
Some of the other entries are preserved in this document from the Alaska State Museum. You can see a really interesting range of ideas here. None of them as good as the actual flag, of course.
(designer: Mary Walsh)