either Minthara does not have a tadpole, or there is an oversight. The Warlock Tadpole ability allows you to teleport to anyone who has a Tadpole. This is implemented almost completely comprehensively, you can teleport to all friendly companions, as well as enemies that have a tadpole. All of the "True Soul" Goblins can be teleported to, the Flind can be teleported to. The dead NPC you run into just outside of the druid camp can be teleported to. It seems unusual for them to so comprehensively implement a mechanic, going so far as allowing you to teleport to corpses of NPCs that possessed a tadpole, but not give it to the "Cleric of the Absolute."
If this mechanic is implemented as comprehensively as I think it is, you can use this warlock power to test NPCs for tadpoles without knowing anything about the NPC, because if they have one, you can teleport to them. Similarly, you can figure out who is branded by the Absolute by using the "Shield of the Absolute" power on NPCs. If they have a mark, they will not be afflicted with Bane, if they do have a mark, they are afflicted by bane. Its an interesting subtle gameplay mechanic that I hope they expand upon more as a "meta" method to learn information about NPCs.
Well she seems to be a fully devout cleric, and iirc a tadpole never spawn from her when i've killed her, maybe she's intentionally kept that way to make for a better infiltrator. Ethel could sus out something was up so any other moderately powerful being should be able to the moment they meet a host as well.
