What is the expiation for the days the questioner did not fast in the first Ramadan that was obligatory upon her, knowing that she does not remember the reason and is not certain about her fasting, and what is the ruling on the days she intentionally broke her fast and did not make them up in the second Ramadan, and must she make up the day she drank water without knowing whether dawn had broken or not?

Intentionally breaking the fast in Ramadan without a valid excuse is a grave sin. One must repent and make up the missed days. Additionally, one must feed a poor person for each day as expiation for delaying the making up of the fasts, unless the person was ignorant of the impermissibility of the delay. If there is doubt about the number of days missed, one must make up the larger number. Drinking water when in doubt about the dawn breaking does not invalidate the fast, unless one becomes certain that dawn has broken, because the default assumption is that night still remains.