Reading as a kid, I was fascinated by the magic of her cures and by how naughty some of these kids were! I also felt a little guilty here and there, as I recognized myself in some of the stories. I was the kid who had the chronically messy room and back-talked her parents. I was secretly glad that my parents didn't have access to a real-life Mrs. Piggle-Wiggle, because I didn't want to be a victim of those magical spells!
As an adult, I appreciate her wisdom in caring for children. Mrs. Piggle-Wiggle was extremely understanding of children, their feelings and their thought processes. She loved them unconditionally, which is all children really want, along with freedom within established boundaries. I think that part of my core of understanding and loving children, despite their imperfections, is due in part to reading these books so much as a kid. I had aspirations, even back then, of being a sort of Mrs. Piggle-Wiggle when I was older.
Some of these stories were "translated" into picture books of individual stories. I have read both the picture books and the chapter books in my classroom with kindergartners and with older kids whom I nannied. All of the children have loved them almost as much as I do.
My favorite of the series was the fourth book, Mrs. Piggle-Wiggle's Magic. My copy had a purple cover, which is my favorite color, and probably helped my attraction to it. This is the story in which the children are all visiting Mrs. Piggle-Wiggle's house. She is out of money, but is convinced that Mr. Piggle-Wiggle still has some more hidden somewhere for her. The children go on a quest to help her find it, even though it is pouring rain.
My least favorite was Mrs. Piggle-Wiggle's Farm. The pictures were drawn by Maurice Sendak, where the other books were illustrated by Hilary Knight. Between different drawings and a different location, the book has a different feel to it. I do enjoy the animal characters in it, though.
A fifth book, Happy Birthday, Mrs. Piggle-Wiggle came out a few years ago. This was primarily written by Betty's daughter. It includes one story actually written by Betty MacDonald. The rest are based on her notes. It also has a different feel to it, but is still entertaining.