I think there is a very distinct break after the paragraph which ends "....must make her happier." Prior to that we are with Anne's thoughts or the Narrator describing them.

From "Frederick Wentworth had used such words...." onwards we are with FW's thoughts or the Narrator's description of them.

JA does use a lot of slippery transitions between different points of view, but this one seems clear to me. I actually drew a line right across the page to mark the change between these two paragraphs when I was reading through this week's chapters.