While that might be true, she wasn't knowingly facilitating a crime, therefore she's not complicit. At most, the parents might be libel for civil damages as Kyle is a minor. But they won't be libel for criminal offenses unless you can prove they knowingly aided and abetted Kyle in the acts he committed. It's going to be impossible to prove they knew before hand he would be involved in shootings. If he's tried as an adult, they are off the hook for civil claims too...
You do not know that. You are speculating. I can wait for the charges and courts.