Yep. She definitely knows Obi-wan is telling the truth, and that Obi-wan went through his process to make up his mind that Anakin is not salvageable (Also Obi-wan loves Anakin too, but made the exact opposite decision as Padme, and from a certain point of view it's not rational decision either) But I don't think it registers for Padme the true extent of his evil until she directly confronts Anakin about it, speaks to him face to face. "He said- he told me you turned to the dark side, that you murdered Jedi . . . even younglings" Like she's trying to gauge his reaction to it.