But how could she shield them from anyone when their own actions had left her a useless puppet? Egwene doesn't seem to think hiding the spies from the Hall was a crime. Siuan even mentions the eminently logical reason of fearing the Black Ajah. That won't stop the Hall from being unreasonable, and Egwene had no way to stop them. She planned to stay silent about their actions, but she did intend to use them to ensure that these women treated her as they are supposed to treat an Amyrlin.

Also, an Oath of Fealty, especially from an Aes Sedai, is vastly different from an Oath of absolute obedience.