She needs to rot in prison for the rest of her life. She destroyed a family. She is a selfish brat who thought it was perfectly OK to kill an innocent woman because she (the brat) was having a hissy fit.
And she wasn't "lovesick" -- she doesn't have any idea what love is. How do you know, at 16, what love is?
I'll bet her parents always gave her whatever she wanted and continually told her how wonderful she is to keep their little darling's "self-esteem" up. No wonder she turned out to be a self-centered child who put "I want I want I want!" ahead of another human life.
The wrong one died. And she was a mother of three. A family ruined. A tragic, stupid loss.
What a selfish, horrible girl. But hey...she's a rich bitch who killed a Mexican who probably has parents who'll hire her the best lawyers so she'll probably get away with it anyway.