In Chapter 48, Pip watches the housekeeper at Mr. Jaggers' residence and notices with surprise that she seems familiar - "her hands were Estella's hands, and her eyes were Estella's eyes". He becomes convinced "that this woman was Estella's mother".
Later, as they walk home, Pip questions Wemmick about Molly. Wemmick tells Pip that "a score or so of years ago", Molly was tried for murder and acquitted, and Jaggers was her lawyer. Molly had been accused of murdering another woman in a fit of jealousy; both women had "led tramping lives", and Molly had been married very young "to a tramping man". Another interesting aspect about Molly's story, although it did not figure in the trial, is that she allegedly had had a child, whom she "frantically destroyed" to get back at her husband. Pip, suspecting that Estella is that child, asks Wemmick if the child was a boy or a girl, and Wemmick confirms that it was a girl. Unfortunately, Wemmick can or will not tell Pip anything more, and they part with Pip having "new matter for (his) thoughts, though with no relief from the old" (Chapter 48).