If Estella had remained with her birth parents, she would have been brought up as the daughter of a convicted criminal (Magwitch) and a woman accused of murder (Molly); however she might very well have been better for it. Instead, she is sent for adoption and is brought up by Miss Havisham who manipulates her and deforms her character. By the time we meet Estella in the novel, she is cruel and heartless and seemingly unable to make good choices for herself. Estella eventually turns on Miss Havisham and the near repetition of 'made' and 'make' strongly reinforces the idea that Estella is the creation of another. She obviously feels intensely about what has happened to her and uses the word 'must' to indicate the depth of her feelings. However, she takes no responsibility for the 'success' or 'failure' of Miss Havisham's experiment.