De acordo com a novelização (Disney canon), a razão para não saber sobre os gêmeos - ou até mesmo o sexo do bebê - foi que ela queria ser surpreendida :
“He?” Anakin asked mildly. “I thought you’d ordered your medical droid not to spoil the surprise.”
“Oh, I didn’t get this from the Emdee. It’s my …” Her smile went softly sly. “… motherly intuition.”
He felt a sudden pulse against his palm and laughed. “Motherly intuition, huh? With a kick that hard? Definitely a girl.”
(ROTS novelization by Matthew Stover, Chapter 12, "Not from a Jedi")
Por favor, note que isso é uma coisa normal na prática médica da Terra até hoje, quando temos ultra-som . Toneladas de pessoas que conheço decidiram não descobrir. Presumo que os médicos da Terra digam pelo menos alguma coisa sobre os gêmeos por motivos de risco médico, mas, novamente, ele é um ser humano, NÃO um "dróide médico" que pode ser condenado a calar a boca.
Aparentemente, ela nunca descobriu e manteve uma surpresa:
“If it’s a girl …,” she gasped, “name her Leia …”
One of the surgical droids circled out from behind the tent, cradling in its padded arms a tiny infant, already swabbed clean and breathing, but without even the hint of tears.
The droid announced softly, “It’s a boy.”
Padmé reached for him with her trembling free hand, but she had no strength to take him; she could only touch her fingers to the baby’s forehead.
She smiled weakly. “Luke …”
(ROTS novelization by Matthew Stover, Chapter 21, "A New Jedi Order")
...
A Junior Novelization of ROTS da Disney por Patricia C. Wrede é ainda mais explícita na medida em que ela nem sequer consultou um droid médico em primeiro lugar. :Padmé laughed. “He keeps kicking.”
“He?” Anakin’s eyes widened. “Why do you think it’s a boy?”
“My motherly intuition,” Padmé teased. Even if she’d consulted a medical droid, she wouldn’t have asked. Wondering whether she carried a boy or a girl had been one of the few, secret pleasures she had during the long months Anakin had been away.