11 year old Stone-throwing girl escapes trial?

[C-Mac]

http://news.bbc.co.uk/2/hi/americas/4744025.stm
An 11-year-old US girl has been spared a felony trial for throwing a stone at boys pelting her with water balloons.
Maribel Cuevas was given informal probation and ordered to talk through what happened with the boy she injured, in a deal agreed by lawyers.
She spent five days in detention and a month under house arrest after being detained in a major police operation.
Police in California said it had been a serious assault, but others said it was no way to treat a childish crime.
The girl's lawyer, Richard Beshwate, said the deal had been agreed ahead of her felony trial on a charge of assault with a deadly weapon, which was due to start on Wednesday.
Under the deal, she will not be required to admit to a criminal offence.
But she will have to attend a Victim Offender Reconciliation Programme, part of which would involve sitting down with eight-year-old Elijah Vang, whom she wounded, and talking about what happened.
"I think everything will be fine," said Maribel's father, Martin, after the proceeding. "This way she'll be able to stay with my wife and me and go to school normally".
Police responded with three cars and a helicopter after the 11-year-old threw a stone at a group of boys who rode by on their bikes and pelted her and her brother with water balloons.
Cuevas supporters said police were criminalising childish behaviour
Maribel, who speaks little English, was read her rights twice in English before being detained.
Police defended their actions, describing the stone as a "jagged-edged, two-pound river rock" that left Elijah Vang with such a deep gash he needed to have stitches.
During her five days in detention, Maribel was reportedly granted one 30-minute visit by her parents.
At the time, Mr Beshwate accused the authorities of "treating her like a violent parole offender."
"It's not a felony, it's an 11-year-old acting like an 11-year-old," he said.
The confrontation happened in late April in a poor district of Fresno, central California, where the girl lives with her Spanish-speaking family.

What am I missing here?
Number one, would this not be a form of self defense?
Second, haven't we all commited this crime, just not being as good a shot as a her?
Must be more to this for this is bizazare, the girl is only 11.

[Dayze]

if it were a boy throwing the stones, he would have been in juvenile detention until he was 18.