I strongly disagree, I think it makes sense that you don't always get the same rewards when you pick the "good" option. Always getting the same results regardless of your choices means the game would only contain the illusion of choice, because real choice has consequences. They do give you an inspiration dice as a reward for redeeming her, which is much more fitting in the context of what actually happens here. The fact that the reward differs based on the choices you make improves the game in my opinion.
In real life when you help people, they don't always give you their most valuable possession in thanks. It makes sense that Kagha only gives up her magic necklace if you take it off her dead corpse. It's not like she asked you to intervene, or owes you something personally. Her focus is on the shock of what just happened, she becomes distraught in regard to her own actions, it would be strange and out of place for her to start talking about giving you reward when she has just been outed as a traitor to the grove.
