Did increasing the insulin dosage for an elderly father lead to his death, and is expiation (kaffarah) obligatory for the the daughter?

One must consult a specialized doctor to determine the cause of death. If the doctor states that the overdose was not the cause, then she bears no responsibility. If it was the cause, and her action was based on the doctor's instructions, then she also bears no responsibility. However, if she did so of her own accord, she is negligent and owes the blood money (diyah) and expiation for accidental killing, unless another cause for death is probable, in which case she is not liable. In all circumstances, she must repent and seek forgiveness.