May 30th, 1889 — Hogwarts Coming Out Ball
Kate hadn't been invited here, but Mrs. Daws, the widow who their father had hired to act as her and Isaac's chaperone while they sat around waiting for a Hogwarts letter, had. She typically didn't go to these sorts of things, she said — which was reasonable, since she had no children of her own and no current interest in society. Kate had convinced her to go this year, though, and to take Kate as her "plus one;" not for the sake of the ball, but because Katherine was desperate to see this school she'd heard so much about. Isaac was too young to get away with coming, but she'd promised to do some reconnaissance and tell him all about it.
She had worn a dress she'd brought with her from Morocco - a comfortable and modest one made of blue and white. Buying a dress would have seemed too much like she was going to a ball to... do ball things, which wasn't really her intention.
She'd left Mrs. Daws for only a moment, to get a drink from the refreshment table. The ball had only just started, and the main event — which she knew nothing about but gathered involved some girls and a staircase — had not yet begun. Someone she passed was talking; she overheard the phrase she isn't out yet. It struck her as an odd thing to say. Out of where?
After having retrieved her drink, she returned to her chaperone and asked curiously, "What does it mean when someone says a girl is out?" She realized only as she said it that the person she'd addressed wasn't Mrs. Daws at all, but only someone wearing the same color. How embarrassing!