There has to be a place to draw the line.  What happens to the parent with an uncontrollable teen with a fuck you attitude who does something just to get the parent fined?

We're such hypocrites about whether or not kids are adults.  We want to try them as adults if they commit a crime, but if they don't have any money, we want to sue their parents.  If it's my kid who does something wrong, they're a child, but if it's your kid, they're a hardened criminal who should get the death penalty. ;)  

I don't know what the rules should be, but we should really decide exactly where we're gonna draw that line before we hand out penalties.

"It was an ancient rule of Hawaiians that no one should hurt another bodily, or through theft of goods or through injury to feelings.These were the only sins."

According to the main, and most current link (charged a mother with second degree manslaughter), Shawn Ledesma was charged with vehicular homicide.  I think the questions here are, how much of a penalty should the mother bear for a lack of good judgment and can the state make the charges brought stick?  I don't believe she deserves to face the sort of serious jail time that second degree manslaughter brings; it would seem to me the appropriate charge would be failure to properly supervise a minor.  I am reminded of the age-old saw that says a prosecutor can indict a ham sandwich; it's another thing to get that ham sandwich convicted by a jury of humans who would rather eat it than send it to jail.  In my mind, there are two bad things that could occur because the prosecutor decided to overreach himself with the charges against Ledesma: the state could get a conviction and the woman unjustly pay for what the son did or the state could fail to get a conviction and the woman escape totally from bearing any cost for what her failure in judgment caused.

Illegitimi non carborundum.

Well, the son did kill someone, however accidentally, and the mother did make it possible for the son to do that, by giving him the keys when he was not legally permitted to drive unsupervised.  In general, when people do things that are illegal, we inflict legal penalties in order to discourage other people from doing the same thing, as well as to discourage the people who are being penalized from doing the same thing again.  

Let us imagine that instead of giving her son the keys to the car, the mother gave him a loaded gun, for which neither he nor she had a permit, and he then took the gun and went out and killed someone for looking at him funny.  We could still ask, what good would it do to put either the mother or son in jail?  It is not going to bring the murdered person back to life.  And the prisons are overcrowded and very expensive.  Still, we don't want to give the killer, or any other prospective killers, the idea that they can murder people with impunity.  It creates a bad precedent.

The fact that the death was caused accidentally with a car rather than deliberately with a gun makes it a less serious offense, but it is still requires a serious penalty.  We could debate whether jail is the right penalty.  But it probably is the penalty which would best give pause to other mothers who consider allowing their children who are just learning how to drive, to do so illegally without supervision.