Showing Anne of Windy Poplars by L. M. Montgomery

This volume contains the two books that most "Anne of Green Gables" collections miss:
Anne of Windy Poplars
Anne of Ingleside
Although written almost 30 years after the first books of the series, they are chronologically #4 and #6.
Anne of Windy Poplars takes place over the three years between Anne's graduation from Redmond College and her marriage to Gilbert Blythe, and cover the ages of 22 to 25. While Gilbert is in medical school, Anne takes a job as the principal of Summerside High School, where she also teaches.

Anne of Ingleside takes place seven years after the end of Anne's House of Dreams, and covers Anne between the ages of 34 and 40.
Anne visits Diana Wright and her daughter, Anne Cordelia, in Avonlea following the funeral of Gilbert's father. When she returns home to the old Morgan house, now named "Ingleside", she is greeted by her five children. The book includes the dreadful, seemingly eternal visit of Gilbert's disagreeable, oversensitive aunt Mary Maria Blythe, whose visit was only supposed to last two weeks but stretches on for months. At the end of the book, Anne worries that Gilbert has grown distant and possibly doesn't love her anymore...