Are we sure that Aesudan has no relationship with Sadeas. It would make sense from a politics standpoint to join their houses together to try and help stabilize Alethkar. It would also provide future intrigue with Adolin's actions at the end of WoR. In terms of why Jasnah was suspicious of Aesudan, is there a way that Ivory could have noticed some kind of influence from Odium and was trying to get a message to her warning about the influence.