What kind of killing occurred, and what are the expiation (kaffarah) and blood money (diyah) required for an unintentional run-over accident involving a child, and is insurance sufficient in place of blood money?

If the situation is as described, then this is not involuntary manslaughter, nor does it necessitate blood money (diyya) or expiation (kaffarah). Rather, it is negligence on the part of the person responsible for the child's care. Assuming the killing was, in fact, accidental manslaughter, then it requires fasting for sixty days, and the blood money for a child is the same as that for an adult.