She vowed to name her son Yahya, then she went against her vow and named him 'Abd al-Rahman. What is the ruling on her action?

Question:
May Allah reward you with good, and may He do you good as well. In the chapter on vows, a female listener asks and says: A woman said, “I have a vow upon me to Allah that if I give birth to a son, I will name him Yahya, and if I give birth to a daughter, I will name her Maryam.” She gave birth to a son, but I named him 'Abd al-Rahman. Do I owe an expiation for that, or what do you advise me to do? May Allah reward you with good.

Answer:
This is a vow regarding a permissible matter, in which a person is given the choice between fulfilling it and paying the expiation for an oath. Since you went against this vow and named your child other than the name you vowed to give him, you must pay the expiation for an oath: feeding ten poor people, clothing them, or freeing a slave. You have the choice among these three. If you are unable to do any of them, it is obligatory for you to fast for three days. Yes.