What is the ruling on fasting a full month, consecutively or intermittently, to fulfill a vow made at the age of sixteen, given ignorance of the rulings concerning vows, and is it permissible to interrupt it because the husband does not allow fasting on days he is present?

She must obey Allah and fulfill the vow if she knew that committing to obedience in order to obtain a certain matter is considered a vow. However, if she was ignorant, then there is nothing upon her. If it is determined to be a vow, then continuous fasting is not obligatory unless the intention of continuous fasting is certain. The husband's right takes precedence over fulfilling the vow, so if he prevents her, she must not disobey him, especially since the vow was made without his permission. She must seek her husband's permission or wait for another opportunity. She is obligated to fulfill the vow if she was an adult at the time of the vow and was not excused by ignorance.