Sansa/Arya
Lyanna Mormont is one of the toughest women we know, and she ran an Island on her own, and she was younger than you when we went to Winterfell. She should be your Master of War. Brienne is here as well and since Bran is not if you wanted her in charge of the Queensguard, I would not be offended, if you want me in charge, she should at least still serve as a member.