2,816. Girls Age 12
Hilchos Nedarim 11:6
The previous statement that vows made by a girl 12 years and one day old are effective apply when she is not in the domain of her father or her husband. If she is in her father’s domain, even if she reached the age of maidenhood (which is 12), her father can annul all of her vows and oaths on the day that he hears of them, as per Numbers 30:6, “All of her vows and prohibitions (are annulled)... because her father restrained her.”
Hilchos Nedarim 11:7
Her father can annul her vows until she reaches the age of adulthood (which is 12½). Once she reaches the age of majority, he can no longer do so. Rather, her vows and oaths are like those of a widow or a divorcee, as per Numbers 30:10, “All that she prohibited upon herself (shall be upheld).”