In Fahrenheit 451, what does Montag think about the old woman on Elm who chooses to die with her books, and where is this found in the book?

You can find this incident towards the end of Part
1.

At first, Montag goes into the house on Elm St. as a
committed fireman.  He goes in intending to destroy the books and the house.  He gets
annoyed with the old woman because she is not playing along -- he wants to do things the
right way.  This shows that he is still a normal
fireman.

But then something happens.  The woman starts to
talk about how she is not going to leave and she implies she's going to die with her
books.  This bothers Montag and he starts trying to persuade her to leave.  Clearly, his
thinking has changed.

Later, he is talking to Millie about
the woman.  He is disturbed by what has happned and he has started to wonder if there
must be something important about books -- otherwise, why would that woman die for
them?

So the interaction with the woman really changes his
thinking about her and about his whole society.