Gu Chaoyan was not an important target, no matter what she did. She was not better than Gu Ruxue anyway, so why bother to talk about her?
What troubled Honored Princess Jing above all was the Queen.
She knew pretty well that the King had been making use of the Queen so he pretended to be kind-hearted for her. She had not been worried about his affection in the past. What she had been doing was to plan the future for her son Ling.
However, now she realized that the King had fallen for the Queen, and that he could not leave her. Otherwise he would not have mentioned the heir in front of the Queen.
It basically meant that the King had gotten the slightest idea of making Lord Huai the heir. However, because of her and her Aunt, the King had gotten rid of the idea, but Honored Princess Jing was unsure whether the King would come up with the same idea again and when that happened, she might not even be able to stop him on time.