Maybe a course of action is to make the party track the mother (who has left the village if I understand your story correctly). Aside from obvious survival checks, you could make some sort of twist here, make the village have cast her out since she was starting to ramble and they accused her of witchcraft? Hopefully, the party will believe the village to be some sort of superstitious lot, but after meeting the mother and her betrayal find out that the village was right after all. Afer finding some 'rambling' in writing or so, they could get some sort of clue as to which direction the mother took.

Alternatively, the Ki'Nau could've raided the village (or raid it with the mother still there), ostensibly for some other purpose but in reality to bring the mother back with them, which might lead to tracking, fighting scouting parties, etc. Maybe play into some of the party members' abilities or backstory. In my current campaign I have something similar (the party needs to find pieces of an amulet) which are all related to their backstories. Eventually, it'll lead them, hopefully, to the realisation that they were brought together without their knowledge for this purpose.