What it means in Canada is that there is no such thing as a statute of limitations for the indictable offense of criminal negligence resulting in bodily harm. What it also means is that Elly would possibly be convicted because of a legal fiction called 'the reasonable person.' You see, a reasonable person would be expected to know that a four year old child told to ask "someone" if she could leave the property would take that to mean "any random person" instead of "me or Daddy." A reasonable person would not waste team asking a stupid question when it's clear to most people that small children don't understand what storm warnings are. What this means is that any time, someone could just waltz on down to the police station and file a report against Elly for dropping the ball.
Let's make that person Deanna. At some point or other, it would probably become too much to bear to have Elly not be grateful to have Mike boss her around too and she'd nark on her to the cops as a means of punishing her for not loving Mike. We could have Rhetta come in as Elly's mouthpiece wondering why Mike is using Farleygate to hurt the family instead of heal it, Elly doing a lot of soul searching about how she never seemed to have the time for her children even when she had the time, things looking fairly dicey only to have the whole matter resolved because Rhetta pulled a rabbit out of a hat: a recall order on the latching system because it wasn't actually kid-proof. We'd see footage of an employee of Underwriters Laboratory thinking it was latched securely because he tried to force it open from the top only to kneel down to kid height and open it easily. While said rabbit would die because Elly saw April do it, she'd save herself anyway because she told John to fix the latch. We'd have Steve come in, tell everyone he saw John work on the latch and falsely think it was fixed and report a fallacious success to Elly. The end result is that Elly is not on the hook for an indictable offense. She is, however, found guilty of failure to report an accident to authorities and will thus have to spend six months doing community service at the children's hospital.