It made perfect sense.
She'd been battling nausea off and on for days, though she'd blamed her upset stomach on the storm brewing between her and David. A ridiculous lie she'd told herself to put off an inevitable truth. She'd grown up on babushka's traditional cooking and then, later, forced herself to throw up nearly half of everything she ate to compete with the other principals for prime parts. Natasha had a cast iron stomach. Except, apparently, when she was pregnant.