“Not me!” Lydia cheered, as Clara grumpily went back to eating her pizza. “I’m very excited about my birthday next year!” “Good!” Her mother and I said, “That’s the right attitude. Why are you excited about your birthday this year?” “Because…” She poked a thumb at her chest as it swelled proudly. “I get to have TWO birthdays this year.” Andrea and I shared a confused look. “How is that?” “Because…” She bowed and waved an arm elegantly. “Clara agreed that she and I are twins. And that means her birthday is now my birthday too.” Clara suddenly stopped eating her pizza and straightened in her chair. She stared wide-eyed at the wall in front of her. “What?” she said finally after swallowing hard.…