Kill her with kindness

I was telling daughter A. not to be angry with another girl at school who gets on A's last nerve.  I told her not to waste her energy being angry; instead, kill the other girl with kindness.  A little while later I heard A. say to Son D, "I am going to do what mom said and kill ____ with kindness.  She should be dead on Tues.!"  Don't you just love the way kids look at things!