Is blood money obligatory upon a mother if her infant daughter dies due to her sleeping alone in a cold room, knowing that the father has forgiven the blood money?

Leaving a four-month-old child to sleep alone in a room is an act of negligence. The mother is obligated to atone for this negligence, which is to free a slave. If she cannot find one, then she must fast for two consecutive months. The blood money (Diyya) would be borne by the 'Aqila (male relatives on the father's side), but since the heir has forgiven, there is no Diyya upon them.