Charlotte F. answered 03/30/19
Cambridge English Graduate Available to Tutor English Literature
It is quite possible that Celia's nickname for Dorothea, which is indeed "Dodo," is meant to suggest that she is an outdated character. Celia certainly maintains that Dorothea is misguided. Perhaps take a look at the various criticisms that Celia offers of her sister. However, I think Eliot's representation of Dorothea as Saint Theresa (note: it is not Mother Theresa) is much subtler than a connection between the Dodo as a symbol as extinction and obsolescence and saintliness would allow. Take a look at the Prelude to get a sense of the narrator's gently mocking position on Saint Theresas.