Great points - I don't think it's unreasonable for society to assume that even somebody who claims accident but waits over 30 days to "admit" it, would be seen as guilty of manslaughter. A mother whose child dies from an accident is duty-bound to report the situation to medical authorities (unless she is a doctor or coroner) to give them an attempt to revive the child or to assess the cause. If it indeed were an accident, what responsbility did she assume to have the child treated or examined by professionals? I don't think it's unfair to assume that is felony child abuse and since the child died, (and the "accident" was never confirmed by a professional), it would seem prudent it was automatically charge felony manslaughter - given that the child is under 12, it is automatically murder in FL. No need for premeditation deliberation.
When you decide not to report an accidental fatality of a minor, guess what? The state can assume its manslaughter or murder. Any other conclusion is unfair to the victim, who cannot speak for themselves, and even if alive, might not be able to. Guardians and caretakers do have the burden of proof when it comes to explaining harm that has befallen children. Too bad - it's parental accountability - and despite that, the world is full of children who are exploited or harmed anyway.
When you are considering children, the rules change; all of us with kids or without are well aware of that need in today's society. That fact right there puts this case in another category entirely and makes other analogies to murders - unless they involve children - irrelevant and useless, imo.