Who was really to blame for Elizabeth's death?
Aunt Agatha poured poison in George's ear that was actually the truth [See, George, what you get when you're nasty to the elderly?]. Then Ross suggested she should have another baby and have it be premature, too. Next we had Geoffrey Charles, trying to be cute saying how much Valentine looks like Uncle Ross. There's the doctor that gave her the stuff, but he also warned her if the contractions didn't stop she needed to tell her doctor what she took. Her doctor, Dr. Behenna just let Elizabeth lay there for a week getting worse and smelling worse and did nothing. And finally there was Elizabeth, who when asked by Dwight if she had taken anything lied because George was sitting next to her that she hadn't taken anything.
I think in the end the one to blame for Elizabeth's death is Elizabeth. She was warned of side effects and told to tell her doctor what she took if something went wrong and she didn't do it. If she'd been honest, she might have been saved. Even that quack, Behenna might have done something to save her if she'd just been honest.