Betty MacDonald was an American author who specialized in humorous autobiographical tales, and is best known for her book The Egg and I. She also wrote the Mrs. Piggle-Wiggle series of children's books.
I have read the Mrs. Piggle-Wiggle series, but I've never heard of mickaboo full of Bojanes phrase you are referring to. Of course, it's been more than 50 years since I've read the books, so....I could have forgotten.
I did a Bing search of the phrase and come up with mickaboo being a type of bird. Sorry I wasn't more helpful.