It is interesting to compare these two characters and identify similarities, because on the one hand Elaine and Cordelia could not be more different. It is, after all, Cordelia that leads the bullying and victimising of Elaine that haunts her even up to the present. However, looking carefully at the book as a whole, it can be argued that one of the things that Elaine realises as she trawls back through her memories is that they are not that different as characters after all, and in particular, when they meet again, and the tables are turned, Elaine has developed some of the capacity to hurt and wound with what she says like Cordelia used to do. Note for example that Elaine as a middle-aged woman does not think she is a good person, even though she helps a drunk woman out. She is well aware that what she and Cordelia share is a capacity for negative characteristics that links them together. Note what Elaine says about herself after helping this woman:

I'm a fool, to confuse this with goodness. I am not good.
I know too much to be good. I know myself.
I know myself to be vengeful, greedy, secretive and sly.

What Elaine and Cordelia therefore both share is a recognition of their negative qualities. Both, after all, in different contexts, use their power to hurt and wound others, even though arguably Elaine does not do so to the same extent as Cordelia did to her. Both, as well, go through something of a breakdown in their adult life, with Elaine's final memory of Cordelia being when she visited her in a home for the mentally ill. Both have gone through periods in their life when they are victims, and clearly this impacts them greatly.