Who is Watching the Children?

An infant and his two-year-old sister are found dead in a house shared by two families. At first, they are believed to have died from carbon monoxide poisoning or cold medicine overdoses. When Dr. G. examines the infant, she finds no apparent cause of death. However, when she examines the two-year-old, she finds teeth imprints on the insides of the child's mouth, indicating that someone had suffocated her. Since the girl's infant brother has no teeth, Dr. G assumes that he too was suffocated. After the police verify the alibis of all the adults living in the house, a 12-year-old girl from the other family living in the house becomes the prime suspect. At first she admits to committing the crime, but later denies it. The neighborhood is outraged that the police would accuse a child of murder, so the girl is sent to live with her grandparents. Not long after the girl moves in with her grandparents, the family dog is found dead. Dr. G must do an autopsy on the dog to find out whether it too has a been suffocated, and if that will be a significant piece of evidence in convincing a jury that the girl is guilty.A 25-year-old pregnant mother checks into a homeless shelter, and reports that she has ovarian cancer. A week later, she falls ill and dies on the way to the hospital. Dr. G first checks the woman's ovaries, but finds no evidence that the woman ever had ovarian cancer. The woman was overweight and had an enlarged heart, which meant that she was at risk of having high blood pressure and and developing blood clots. Were these risk factors what caused the young mother's untimely death?