Like your #2, and #3
"1。爱打小报告的人都是under tasked 的人,就是闲的发慌,才会有多余时间观察别人的一举一动。你要和上司强力推荐她的能力,建议对她委以重任,多给她一点project做,当然要让她觉得只有她这么有技术的人才能担任,使她觉得被重视才会乐兹兹地去做。
In general, the snitch is a divisive force in a team's dynamic. Do you still want/recommend to reward a snitch with a big/important assignement, which may encourage her/him to continue such destructive behavior and potentially cost a team's high turnover?