What is the expiation for a girl aborting her fetus in the fourth month by taking abortifacient drugs, knowing full well that she is doing so, and being unable to fast for two consecutive months?

A woman sins by intentionally aborting her fetus after knowing that the medicine will cause its expulsion. She must offer sincere repentance to Allah. Her [male] kin (aqilah) must pay the blood money (diyah) for the fetus, which is half a tenth of its mother's blood money. There is a difference of opinion regarding the obligation of expiation (kaffarah) upon her. The more cautious approach is for her to expiate by freeing a slave. If she is unable to do so, then by fasting for two consecutive months. Otherwise, nothing is incumbent upon her except repentance and seeking forgiveness.