When should a breastfeeding woman make up for the Ramadan fast, and is there a Prophetic حديث (narration) concerning a woman who gives birth to twins?

If you broke your fast due to breastfeeding, it is impermissible unless fasting would harm you or the infant. Otherwise, you must repent, and you are obliged to make up the days you missed fasting when possible. If the breaking of the fast was solely due to fear for the infant, then their guardian must feed a poor person for each day, in addition to your obligation to make up the fast. There is no specific prophetic tradition concerning a woman who gave birth to twins, but the virtue of caring for and raising children is established by abundant evidence.