Doorways

Q In Neil Gaiman's book Neverwhere, how many times does Door (Lord Portico's eldest daughter) curl up comfortably with a copy of Jane Austen's Mansfield Park¹ which she has just found on a shelf in a room familiar to her hosts, they all unsuspecting any such book was ever there?

A Twice. Once at Richard Mayhew's apartment, then again at Blackfriars.

_¹SparkNote