I just go to the bit in the re-read where they return and Suian claims that even an infant wouldn't have been tricked. I personally think that obedience to Aes Sedai is pushed so hard, and the idea that one of them would want to harm them so alien that I can't blame them, but she apparently felt...
Liandrin was Aes Sedai. They'd had obedience to Aes Sedai drummed into their heads
Did she lie? I think she seemed to try hard to actually be truthful
Edit - sorry Toral, accidentally 'edited' instead of replied - darned moderatorness!