Girls say that their feelings are complicated, but they don't know how to express them, and they don't know if they should find someone to vent. What should I do? Chatting with her on WeChat?

You can try to communicate with her, because the process of communication is also the process of her seeking correct expression. At the same time, through communication, she can vent some negative emotions of dissatisfaction, resentment or regret accumulated in her heart.

After venting, she will get rid of some negative emotions.