Although filicide or familicide tragically does occur - deliberate homicide committed by the mother is highly associated with severe mental illness with psychotic features. It is extremely atypical for a mother to commit filicide without any overt psychiatric illness. The only case I can think of is Diane Downs, who is an extremely interesting outlier in forensic psychology. Gaylin Rose has demonstrated behavior that is perfectly consistent with a grieving mother and had demonstrated herself to be a wonderful and loving mother.