In most cases in the Torah, the feminine 2nd person word (equiv. to "she" or "her" in English) is written as הוא using a ו and pronounced הִוא .
Avot Derabbi Natan 42:5 lists 11 places in the Torah where the word is written as היא with a yod. (Of notable interest is the 2nd verse that combines writing the word both with a vav, with a yod and the form with a vav used in the masculine form.)
Is there a reason why these situations are made the exceptions? Does anyone discuss a hidden meaning (Midrash, etc.) as to why this happens?