Cheap and effective.
The problem here is that she was a minor when she did the deed and is likely to be released some day.
She'll do it again.
We have tried lenient sentences for juveniles. They don't work, & this imperils society.
I also favor holding BOTH parents, custodial or not, criminally responsible for the actions of their children. If they are gonna have kids, they are responsible to civilize them.
I do not often side with society over individual rights, but in the case of violent perps, young or old, male or female, I believe the safety of society heavily outweighs the rights of a violent felon. IMO, a violent felon forfeits his rights forever the moment he/she commits an unlawful, violent act. A violent felon has no more rights than a rabid dog, & for exactly the same reason. Without humanity they aren't human.