I am currently stuck in the fight with Auntie Ethel: I would really like to save all four enchanted people this time, but the best I could achieve up till now was to save one.

Is there any possibility to remove the masks? I tried pickpocketing, but the masks did not show up in the inventory, and even with Lae'zel, I could not knock them unconscious.
I used Sleep and Hold Person, but of course this does not last long - and I need my spell slots to fight Ethel.
I tried to fight her while we were still in the Gnarled Teahouse, but I never manage to kill her before she disappears at half hitpoints.

Currently, I have my bard, Shadowheart, Astarion and Lae'zel in my party - and none of us has Magic Missile to target Auntie Ethel's clones, unfortunately.

Does anyone know by chance if/how it is possible to fight Auntie Ethel without killing everyone?
Thanks in advance!