Is expiation obligatory for one who fasted on the Day of Doubt in Jordan, then it became clear that the sighting of the crescent moon was mistaken in the countries that adopted that day as the first day of fasting?

The questioner should fast and break their fast according to the moon sighting in the country where they reside. If the month is confirmed there, they should fast; otherwise, they should complete Sha'ban like the people of their country, because the preponderant opinion is to consider the اختلاف المطالع (variation in moon sightings across different regions). If she fasted based on not considering the variation in moon sightings, there is no objection, but she should keep it discreet.

However, if she did not fast with them and fasted the last day of Sha'ban for her country as a precaution for Ramadan, then this day falls into one of two categories:

1. Yaum al-Shakk (Day of Doubt): This is the 30th day of Sha'ban if the sky is cloudy and the crescent moon is not sighted, or if the sighting of the crescent moon is reported by someone whose testimony is not acceptable. Fasting on this day with the intention that it might be from Ramadan is disliked by most scholars, based on the statement of Ammar ibn Yasir: "Whoever fasts on the Day of Doubt has disobobeyed Abu al-Qasim (the Prophet Muhammad) (peace be upon him)." However, if her fasting is supererogatory, a make-up fast, part of continuous fasting, or coincides with a vow, then there is no harm in it.

2. Not Yaum al-Shakk: If it is the last day of Sha'ban, it should also not be fasted due to the confirmed prohibition of anticipating Ramadan by fasting one or two days, except for those who continuously fast, or fast specific days like Monday or Thursday, or are making up fasts, or fulfilling a vow. There is no expiation (kaffarah) due on her for fasting this day.