There is a way to save her from the poison. If I remember correctly, you need to succeed your nature role when you speak with her; that will give you a hint on how to get her antidote. Also, if you steal her boots, then give her the antidote: be prepared for combat.
However, if you don't succeed your roll:
One of the deep gnomes by the shore has her antidote. You can swipe it from him, with a thief; or kill the party of 4
