Princess Playhouse Looking For A Book About Four Sisters, Eldest Cassandra, Whose Governess Starts A School In Their Home. There?

Looking for a book about four sisters, eldest Cassandra, whose governess starts a school in their home. There? - princess playhouse

The nurses have been reluctant to share their homes and their animals, but they persuaded the housekeeper. It was a small theater / den in the forest that was home economics class. It was fifty years ago, and I do not remember the title or author, but I recently read the question from a reader who felt that there was a princess of the word in the title. It's basically a children's book published there over fifty years, I think