Huh. I do enjoy that I keep finding out new things. I have found Ethel's lair in Act 3, on a playthrough were I let her live - BUt there was no Ethel in sight, just a handful of goons.
I'm also on my third dedicated playthrough, but have never seen Kua Toans as mentioned on here, either.
You probably need to start the quest if you haven't.
most of the tenant on the top floor of the bar are her minion, and the "captain" there is her.
.
you let her keep Maryna => she has her child and Maryna fights to get it back.
You save Maryna, spare hag => she is in baldur's gate with another child
You save maryna kill hag => oh, Ethel was immortal she didn't really die
If that's the case, than I really dont understand why we have Ethel in act 3 at all.
She die for real if you burn her 'shroom