When I ask this question I can see that practically everyone can save Lilly at various points in her downfall. In particular, I think that the role played by Seldon is despicable. He is her closest friend and yet it is he who sets in train a series of events which lead to the downfall - commencing with their first meeting in his rooms and his contrivance to keep her from meeting Percy Gryce at church. At the end of the day he does not own up to the part he played in the downfall and nor does he do anything constructive to help her. As for Rosedale, he understands entirely that Lilly is not to blame for any of the charges against her and yet with that knowledge he also fails to do anything about it. She is portrayed as a flippant, flighty party girl but by the end of the book we see that she is the only real good person (perhaps bar Gertie) and the others are ugly parasites who drive her to her ultimate fate.