What does Herbert tell Pip about Magwitch's background in chapter 50? What does Pip conclude after hearing this information?

Magwitch was the husband of Jaggers' servant woman, the Tigress. The woman had come to Magwitch on the day she murdered the other woman and told him she was going to kill their child and that Magwitch would never see the baby again. And Magwitch never did. Pip puts it all together and tells Herbert that Magwitch is Estella's father.