What I've always tried to do with the children is tell them we don't make other people feel bad. Important moral principle which I try to hammer home every day. So yes you might think a boy in the class has funny hair (one in their school has lost all his hair for example) but you never speak about it or mock them because you want people to feel comfortable and most importantly you should treat people as you want them to treat you.
That is a very different point from what I see as PC stuff. I think it's bad if you have a sports day and no one wins or we try too hard to insulate children from reality but within reason. The child bad at everything - sadly there are often some - you have to try to find something they're good at and it's a struggle sometimes but important for their own sense of self.
(By the way I just emailed the student loans' company because on a form we got today they use it's instead of its. Dreadful. They should discipline their proof readers. It will have gone out to every undergraduate in the UK - I hope they all wince when they see it).