Ugh that would be bad for GeorgeXShannon and JessicaXKanon.
Personally i think that the one wing eagle is basically a symbol of trust. Genji, Kanon and Shannon were trusted by Kinzo and thus given the one wing eagle. Naturally, all of his blood relatives would also be given the eagle as he
would should normally trust them.
Meh. I think that a full eagle symbol might actually appear later, since Chiru suggests a laterally inverted one wing eagle. So when solving the mystery, maybe a full eagle might appear? ^^