At least the mom's taking her son seriously. It could be worse. She could not believe him, or she could say, "Fine, go ahead and kill yourself. You'll be doing me a favor. Bringing you into this world was the worst mistake I've ever made."
If she does get charged with criminal wrongdoing and stands trial, the jury could find her guilty. Or the jury could decide to find her innocent on the grounds that her son was so rotten that they could understand why the mother wanted him dead.