"Tired," she says honestly. That isn't what he means, though, so she explains, "Good tired. It feels like I have been in gym class." She means it feels like exercising, like she's flexed a muscle she hasn't used in a long time. "I will need practice to know." That much, she's self-aware enough to know. None of her powers had been immediate. She'd had to work to unlock them, step by step and inch by inch. This, she thinks, will be like that.