Quiet Elizabeth "Beth" DeGraf is fifteen. She lives with her indifferent parents, a music teacher and an embroiderer, in a small town.
Glamorous Louise Merrick is seventeen. She and her mother, impoverished by her father's death, are living high in a nice apartment on the remainder of his life insurance payment rather than eking out a bare existence on the interest, in the hopes that Louise will make a good marriage to support them both.
Freckled redhead Patricia "Patsy" Doyle is sixteen. She and her Irish father, "the Major," live a poor but happy life with her as a ladies' hairdresser and him as a bookkeeper in a tenement house in the city.
At first glance the trio are a disparate lot, but what they have in common is Jane Merrick, a sickly, discontent, rude old lady who is their aunt. When Jane Merrick realizes she is dying, she sends invitations to each of the girls to come live with her for a month. She is planning to decide which of the three is the best heir for the sizeable fortune she inherited from her fiancé, who died on the eve of their wedding and left all his money to her. Dismissive Miss Merrick doesn't even consider it a possibility that the other heir to the estate might be Kenneth Forbes, her intended's nephew, whom she promised her fiancé she would care for if something happened to his mother. Ken is shy, rude, and mostly untutored, and he loathes his "almost aunt" as much as she loathes him.
These wildly divergent personalities come together in the 1906 book Aunt Jane's Nieces written by Edith Van Dyne, and appears typical in writing to the girls' series of the times, although Louise at first seems an atypical heroine for one of them as her character is closer to that of the inevitable opponents the "nice" girls have in other series stories. It will not be much of a spoiler to tell you that, despite the girls' wariness of each other at first meeting, they all are friends by the end of the book, since nine sequels were spawned, including the inevitable World War I era volume that had the three joining the Red Cross. (Almost all children's series fiction had a point where they halted between 1918-1920 and became obsessed with helping out the cause in the Great War, and many more series books were spawned by the adventures of boys who joined the Army and girls who became nurses or who deterred saboteurs.) Into the mix is also tossed the girls' Uncle John, who returns from "the West" rolling in dough from good investments he apparently makes accidentally, and who bankrolls the girls in all of their schemes in the later volumes.
Some of these volumes, however, didn't follow the traditional plots of most girls' novels of the times. Aunt Jane's Nieces at Work, for example, follows the girls as they help Kenneth–who has, under the influence of his now favorite "cousins," become a bit more agreeable–run for office. Politics was a strange bedfellow for three lively girls in that era when women still did not have suffrage, and indeed the pages were full of diatribes about evil grafting politicians and Democratic principals against Republican ones and vice versa. Indeed, several of the Nieces books not only seem to contain a small mystery, but rail against corruption in industry and politics, hardly the usual subjects in girls' books where clothing, society, and parties were the norm.
But then Edith Van Dyne's other books weren't on typical girlish subjects, either. The two volumes about "the Flying Girl," for instance, followed the adventure of a courageous young woman who learned to fly aircraft in the canvas-and-wire era. And the Mary Louise books follow the adventures of a girl who, in her first story, is pitted against detectives and the United States Secret Service (whose agents are portrayed as double-crossing and in competition with each other in an age where Government representatives were usually shown as solid, honest characters) looking for Mary Louise's beloved "Gran'pa Jim" to arrest him for treason! Strong stuff in those days for girls, but they sold well, showing that the young ladies of that day were eager for more than frills and furbelows in their literature. Indeed, Edith Van Dyne must have been a most progressive woman.
Not to fear, the mystery of Edith Van Dyne has long been solved: "she" was a he, in the person of Lyman Frank Baum–yes, the author of The Wonderful Wizard of Oz and its sequels. If you are interested in old girls' series books and would like something a little different from the norm, Aunt Jane's trio would probably suit you, not to mention the intrepid Mary Louise. Gutenberg.org has several of the titles, as does Blackmask.com.
A nice article/biography of Baum.