Harry sighed unhappily as Ginny announced to them that she had become a member of the Order. He'd had no doubts that she'd qualify, but he had hoped that they wouldn't let her join until she was at least of age.

She heard, and gave him that determined look he was so accustomed to.
Later, after the elder Weasleys had retired, Ginny confronted him.
"What was that for, at dinner? Do you expect that I'm going to sit around while you and the rest of the family are off fighting battles?"
"Did you seriously expect me to be happy about this Ginny? Do you want me to have nightmares of you being overcome by Death Eaters, if something went wrong? Because I have enough nightmares already."

"It's a risk we all take" she snapped at him
"But you don't have to!" he exploded, "you're not even of age."
"I may be young, but I passed their tests, didn't I?" she blazed back at him, "I can look after myself!"
Harry deflated somewhat in the face of her fury. "I never meant to imply that I thought you weren't capable of looking after yourself, Ginny. It's just that...you've never seen them in action...what they're capable of..." he trailed off, eyes haunted. "I want you to be here, when all this is over. I can't pretend that I don't love you, and I don't want to see you in any danger, let alone throwing yourself in it."
'These are dangerous times Harry" she retorted, but he words held no bite, touched by the vulnerability in his eyes. "I know that most of the old order died in the last war, but we're better prepared this time. We'll be alright, you just look after yourself."
Harry sighed heavily and pulled her into his arms, pressing his cheek to the top of her head, inhaling her flowery scent
"I'm sorry. For not supporting your decision." he whispered.
"I think I can forgive you. If you promise to try and write while you gone."
"Ginny I can't promise-"
"Please! Just say you'll try. When it's safe."
Harry hesitated for the barest of moments before giving his word, "I promise"
"Thank you," Ginny murmured, "I love you too. And I'll wait for you, no matter how long you're gone."
Her words had the sound of a vow about them, and Harry couldn't help but feel hopeful.