Your character itself is a CharacterBody2D, which is attached to Node2D, that is, in addition, you just need to write after get_child(0) another get_child(index node CharacterBody from top to bottom).
Your character itself is a CharacterBody2D, which is attached to Node2D, that is, in addition, you just need to write after get_child(0) another get_child(index node CharacterBody from top to bottom).