The blind date is neither too hot nor too cold. I deleted her WeChat twice, but she still added me. What does she mean?

Delete her quickly and blacklist her. She is obviously riding a donkey to find a horse, which shows that she is afraid that you will ignore her, but she doesn't particularly like you, but she is afraid that you will lose interest in her. She should take advantage of your kindness and find someone she can look at. If one day she finds out, she won't add you, so don't waste time on her, just hack her and find someone else.