Obviously, Jiao Ke did not say this to Mu Xuexin. She was once envious of Mu Xuexin being able to become Qi Su's fiancee yet she herself wasn't able to have his attention.
However, as Mu Xuexin was a princess, what could she do even if she was jealous? She did not have the courage to resent Mu Xuexin out of jealousy and so shifted her hatred to Qi Su.
Even though she was even perfectly willing to become his concubine, what she received was his cold rejection and lost all her dignity back then.
Luckily the heavens weren't blind, and with Qi Su's backing collapsing, he was expelled from the Qi Family. At that time, she had mocked and ridiculed the siblings, so much so that when no one was paying attention, she secretly gave Qi Ling a beating. If it weren't for Qi Su's timely arrival, she would've ruined Qi Ling's chastity.
