I imagine that this takes place sometime in the middle of A Badge of Bravery, before everyone knows her name.
"Come now! I want you to know how to protect yourself if ever someone tries to hurt you. Now hold it like I showed you yesterday."
Miri grimaced and took the dagger from Edmund's outstretched hand. "I don't like it," she whispered.
"You don't have to like it. But you're holding it wrong."
"I don't remember how to."
"Well not like a kitchen knife!"
Miri's eyes welled up with tears and Lucy finally took pity on the poor girl and came forward from the wall she'd been leaning on. "Oh, Ed. You have to be nice. This is all new to her." She put a hand on Miri's arm. "Here, love, I'll show you. Don't let him scare you."
Edmund looked rather ashamed of himself, eyes falling to the ground. "I'm sorry. It's just...This is important!"
Miri nodded, half extending her hand to take his and then withdrawing it, unsure of herself. "I know," she said softly. "I'll try to do better."
He huffed in amusement and flung an arm around her shoulders. She flinched and Edmund almost pulled away but then she relaxed and held the knife out to Edmund. "Show me again?" She whispered. "Please?"
Edmund smiled and ruffled her short, brown curls. "That's my girl."