She indeed lacked a sense of security... So, she was eager to leave Yan Sijue, because she was afraid she might fall in love with him.
Being despised by her parents as a child was one hurt, and having a crush on Ye Moran as a girl who discarded her like an old shoe was another. Therefore, she was truly scared... She didn't dare to easily give her heart away, especially not to a man like Yan Sijue, whom she had no confidence in controlling. As she began to understand this man more and more, she realized she would fall in love with him sooner or later, and this slowly growing affection would probably become deeper, making it impossible for her to withdraw. Hence, she could only choose to leave him. She admitted that she lacked courage within, but Yan Sijue hadn't given her much confidence either, making her dare not to take the gamble.
