Shadowheart is Neutral Evil, a pragmatic who doesn't have a problem with anything as long as it advance her goals and makes her gain power. If you don't believe me, use your tadpole and in the dream #2 post-conversation, pick "I wanted it all" and then the "which part you liked best" option. She wants power.
Power appeals to her in the dream but I she is also disturbed by its appeal. She is happy to have saved the grove, upset when it burns. She is happy when you save the girl from the hag -- which is not true to type and she's happy when you take on the quest in the first place. Again, why annoy someone dangerous powerful and potentially useful? A true neutral evil character would not care about the rescue, ignore the girl and find out about the cure -- as Astarian wants to do.
And she likes dogs. Evil people hate dogs. Fact! It's even in the terminator so we know it's true.
