I definitely used "kid gloves." The story of Ironic Catholic's 6 year old is precisely what I wished to avoid. That sort of trauma is a parent's privilege that I will not usurp. That being said, my homily was short and went something like this:
Who likes to be picked on? Who likes to be made fun of? Who likes to get hurt by someone else? None of us. Second graders, are you allowed to pick on first graders because they are smaller? "No!" First graders are you allowed to pick on the kindergartners because they are smaller? "No!" Are we ever allowed to hurt someone because they are smaller? What if Mrs Schwab, your principal, announces that it is now okay for bigger kids to hurt smaller kids, would that make it okay? "No!" Because hurting people is wrong, whether we are in second grade or when we are in high school. Even someone so small where we can't even see them should never be hurt by us.
So that's the brief homily. I did mention the anniversary of Roe v. Wade in the intercessions hopefully that was abstract enough to engage the children while concrete enough for the parents to connect what I was saying in the homily. If not, its a good thing the world already has a savior and I am not He.