Should I fast for two consecutive months, or what should I do if my son passed away while I was away from home for two hours, and what is required of me if I am unable to fast?

If a mother causes the death of her child due to negligence, such as being absent from the child until it dies of hunger or thirst, or leaving it in a poorly ventilated place until it suffocates, this is considered accidental killing (Qatl Khata').

Consequently, she is obligated to offer expiation (kaffarah), which is the freeing of a slave. If she cannot find one, then she must fast for two consecutive months. The blood money (diyah) is obligatory upon her 'aqilah (male relatives on the father's side). She must also repent to Allah. However, if it is proven that the death was not due to her causation or negligence, then there is no expiation or blood money upon her.