Louise Brealey making some great points.
She was Mycrofts niece, a bubbly teenage girl but surprising polite. When she isisted that she wanted to visit him he left her for a moment in his room when she found his sword umbrella. With mischief promising eyes she took that umbrella and fighted with the air like a enemy was standing right infront of her. With a serious expression she made quiet fight sounds. "You never going to win thief!" She said in a dramatic voice. Right in this moment he came in with two cups of tea.