1,822. Failure to Exercise the Right of Refusal
Hilchos Geirushin 11:5
If the girl underwent inspection and the physical signs of maturity were not found but she engaged in marital relations after the age when a girl could have developed the signs of maturity, we are concerned that she may have grown and subsequently lost pubic hair. Because of this possibility, a get is needed to dissolve the marriage. If she tries to annul her marriage through refusal after having a physical examination and is subsequently betrothed by someone else, that man must give her a get because of the doubtful situation. If she finalized marriage with him, then both men must give her a get and there is doubt about the legitimacy of a child born with either husband.
Hilchos Geirushin 11:6
If a minor girl doesn’t exercise her right of refusal and reaches the age of majority, she loses the ability even if the couple wasn’t intimate after she reached the age of 12 years and a day. Once she is a legal adult, it is a rabbinic enactment that she requires a get to dissolve the marriage. The reason this is a rabbinic (and not a Biblical) obligation is because they were not intimate after she reached the age of 12, in which case we would be concerned that she might have developed the signs of maturity, which would create the doubt as to whether or not Biblical marriage had been effected. They also weren’t intimate after she reached adulthood (age 12 ½), which would make her a married woman in all ways. Therefore, she only needs a get because of her marriage as a minor, which is of rabbinic origin. Accordingly, if another man betrothed her after she reached adulthood, the second man’s betrothal is effective; if the first husband divorces her, the second may consummate the marriage. However, if the second husband divorces her, the first may not remain married to her. This is out of concern that people will say that he remarried an ex-wife after she was betrothed to someone else (which is prohibited). If the second man was intimate with her before the first divorced her, then each of them must give her a get because it resembles the case where a woman hears that her husband died, re-marries, and her first husband then returns. A child born from the union with the second man would not be illegitimate but if her first husband is intimate with her before the second divorces her, then any child conceived is illegitimate.