Having read this many years ago, I decided to revisit it and found it just as trying a read as I remembered; although it has its rewards for the tenacious reader. It appears that the narrator never met a run-on sentence she didn't like.
As a self-confessed Grammar Nazi, I was surprised to find James' governess use the term "literally" more than once in what I believe is an incorrect manner (she says she "literally slept at her post" when she had not really fallen asleep.) I thought the misuse of this word was modern, as when someone says they "literally lost their mind" when they mean figuratively.
There are also some obscure words ("asseverate") to add to your vocabulary. The edition I read (Wordsworth Classics that also contained The Aspen Papers) has notes in the back to explain references that were probably understood by readers in 1898.
P.S. Although it contains a major spoiler, check out the satiric You Tube video in which Hitler rails against his staff as he asseverates his interpretation of the story.