Is a woman who vowed to the Most Merciful to fast, but did not seek her husband's permission, sinful?

A woman is permitted to make a vow to fast without her husband's permission, and her vow is valid. However, fulfilling it depends on whether it harms the husband or not. If it harms him, she is prevented from fulfilling it, and it remains an obligation upon her until she is able to perform it. If it does not harm him, she is allowed to hasten its fulfillment. It is worth mentioning that vowing is originally disliked.