That's a bit surprising.. cure spells/pods aren't available nor endless, she's not very far in the game.. It sorta makes sense that it lasts longer as it's applied repeatedly, but there's really nothing to do about it when fighting a half dozen worms who all spit.. besides hope that the AI chooses another target or dumb luck they miss, which seems a silly basis for strategy.
I'm a bit startled to find that the answer really is that it's intended, she literally healed at least 30 times, and I'm not exaggerated, trying to stay alive.. I've personally played through all of Avernum 6 and Avadon, and acid was bad, but not THIS bad.. She's not very far in the game and is dying with a startling frequency because of only acid, often after wasting all her essence pods just trying to stay alive.
Anyway.. I appreciate your reply, but it seems pretty.. silly to say the least, especially early in the game.