As far as I can tell, this little girl set was published by Lowe in 1957 (books with numbers right around this one were published that year). Otherwise, I don't know anything about it except that it's adorable.
My book is likely a reprint, given the 15 cent cover price.
My friend Peggy confirms that my book is a reprint. The original set was calle Three Little Maids From School (someone at Lowe was a Gilbert and Sullivan fan, I guess), and it was published in 1957 with the number #2404.
Also- I just noticed that Joan's jammies were printed on 2 pages. Winnie has footie jammies, but poor Ruth doesn't have any (likely there were some in the original- and probably more pages of clothes for all of the dolls).
Click on images to enlarge, right click to save as jpgs. Print from any graphics program, clothes on plain paper, covers on card stock.