Yatori was already far above Ikta in combat skill in this flashback. Ikta could barely fight at all. It looked like he learned to use the crossbow in this very episode. Yatori has probably been learning the sword as soon as she could stand, and was much better with the crossbow as well. They both got much better since then, but I'm not sure you could say there were closer back then. It's just that they both were nothing but children.