Segundo o roteiro, é basicamente um pressentimento.
PADMÉ
Thank you, Master Yoda. Do you have any idea who was behind the attack?
MACE WINDU
Our intelligence points to disgruntled spice miners, on the moons of Naboo.
PADMÉ
I don't wish to disagree but Ithink that Count Dooku was behind it.
There is a stir of surprise.
MACE WINDU
You know, M'Lady, Count Dooku was once a Jedi. He wouldn't assassinate anyone, it is not in his character.
KI-ADI-MUNDI
He is a political idealist, not a murderer.
YODA
In dark times nothing is what it appears to be, but the fact remains Senator, in grave danger you are.
PALPATINE gets up, walks to the window, and looks out at the vast city.
PALPATINE
Count Dooku has always avoided any kind of conflict. It appears he has no desire to start a war. Why would he kill you? To what end?
PADMÉ
I don't know, but everything in my being tells me he was behind it...
After gazing out of the window for several moments Palpatine turns to
Mace.
Realisticamente falando, porém, a República está em conflito com os Separatistas do Comércio, e ela própria já foi alvo dos Separatistas. Com Dookan liderando a oposição que ela acredita estar pronta para a guerra, não é demais acreditar que eles podem ter algo a ver com a tentativa de sua vida.
Também houve teorias no passado, sem evidências concretas (especialmente na Disney Canon) de que Padme possui uma certa sensibilidade à força, o que pode fornecer a ela pelo menos um pouco mais de insight.