Yea, unlike BunBun or Kim (who can become a love interest in chapter 2 regardless of chapter 1 choices), Sweetwater’s story would dead end if you didn’t save her.
Since that is a lot of content to miss, I made a cheat so players do not need to redo their whole save.
I believe that this is written in one of the books in the dungeon. Biography of Frogkin/Water Elementals. Basically a water elemetals is used as a living nursery
Oh yeah, I read it after saving her, but I thought that the protagonist would kill the babies or something like it if we let the "love" happen. Not that she would effectively die.