Chapter 12, from Pip's pov: "I reposed complete confidence in no one but Biddy; but, I told poor Biddy everything. Why it came natural to me to do so, and why Biddy had a deep concern in everything I told her, I did not know then, though I think I know now."
Chapter 19: "Joe and Biddy were very sympathetic and pleasant when I spoke of our approaching separation; but they only referred to it when I did."
Chapter 52, Pip is thinking: [I thought, "Yet Joe, dear Joe, you never tell of it. Long-suffering and loving Joe, you never complain. Nor you, sweet-tempered Biddy!"]
Chapter 58: "But, it was only the pleasanter to turn to Biddy and to Joe, whose great forbearance shone more brightly than before, if that could be, contrasted with this brazen pretender." (Pip's pov)
To search for more quotes from the book, check http://www.online-literature.com/dickens/greatexpectations/
The page number is different for every edition, the chapters are the numbers for an edition not broken up into several volumes.
I hope this helps a bit.