多丽丝缺乏信心。我从未遇到过像她那样没有自信的(unsure of oneself)人。(confidence)

Alice lacks confidence. I have never seen anyone who is unsure of himself or herself like her.

Alice is short of confidence. I've never seen anyone who is as unsure of himself as she is. 

Alice has no confidence in herself. She is the only person I have ever seen who is so unsure of herself. 

Alice has no self-confidence,...

缺乏可用lack，be short of, have no表示。从未见过，，，的人，用定语从句结构翻译。