What is required of one who deliberately broke her fast in Ramadan, not knowing at the time whether or not she had reached puberty?

The signs of puberty for a male are: emission of semen with desire, or the growth of coarse hair around the private parts, or reaching 15 Hijri years of age. A female has the additional sign of menstruation. If you are certain or highly assume that you intentionally broke your fast while having reached puberty, then you must make up the fasts (qada') and repent. You must also pay a fidyah (expiation) of feeding one poor person for each day whose make-up was delayed without a valid excuse until another Ramadan arrived, provided you knew the obligation of making up the fasts before the subsequent Ramadan. However, if you are certain or highly assume that you had not reached puberty when you broke your fast, then there is no obligation upon you. If you are doubtful about having reached puberty, the default is that you are free from liability, and thus no make-up fasts are incumbent upon you.