"It's just polite way of saying/explaining things."? -Warning this is going to be long to read-

After what happened yesterday I seriously have no clue what is "polite" anymore in here.
My youngest sister who is eight years old lost her left eye due an accident with lawn mower before six months ago. This is very traumatizing and difficult experience for anyone, but it is even worst experience for someone so young like my sister. Since then me and my family were trying our best to explain to her that is ok, that there is nothing wrong with her that she is still normal and very capable kid and that she is not now "ugly" (as she called herself) just because missing one eye (my dad even made a joke saying how eyepatch people are most attractive ones). However she is not going to be 24/7h with us, sometimes she is going to need to get out of the house, be it to go outside or to school she is still going to encounter people outside that can be jerks to those different then them.
Thankfully she doesn't encounter bullying in her class(she does look a bit odd to her schoolmates, but lucky for her she has amazing class that doesn't treat her differently just because of an eyepatch). However when I came to pick her up from school, there were two boys that weren't from her class and one of them was showing my sister to his mother by pointing finger at her and other one said "This is pirate girl". Before I got chance to react, mother of child that called my sister pirate explained to her kid that is not nice and that is very rude to make fun of people who are different them him, so far it is what I would say to kid as well until mother added last line to her sentence "If you keep teasing people different then you then God might punish YOU AS WELL by making same thing happening to you."and other mother of the other kid confirmed this and then they apologized to me for their kids being rude??? Hold on ladies, I know you wanted to do some good but do you realize that you right now have said way worst insult to my sister then your kids ever did, because right now you made it sound as if my sister "angered the God" in here somehow and he punished her by taking her eye so lets make example of my sister to all people how not to "anger" that "God" so it doesn't happen to them. I mean seriously ladies, yes you were trying to be "polite" in here and scare your kids in order for them to stop being jerks, but hello, you could have been way more polite and you could have explained your kids just fine not to be jerks without that line to your sentence in end and without you confirming same story as if it was FACT as well.
I seriously wanted to scream that in face to them if not for my sister who was on verge of tears and was urging me to just go, so not to make a scene and not to make my sister feel worst then she already does I swallowed my anger and said to those ladies that there is no problem that they are just kids and kids don't think what they say, also I couldn't resist adding at least line that adults as well many times don't think before they say something before getting in car to drive my sis back home. And on drive home my sister ask me this in tears"Is the reason why I lost eye because God is angry on me and he punished me?" and OMG in that moment I swear I was more red then tomato from anger boiling inside of me that I need to stop a car for few minutes to regain my cool so another more fatal accident doesn't happen in here.
I did my best to calm her down, telling her that is not true, that she is just a kid and that God doesn't hold grudge against kids and trying my best to say to her that her accident doesn't have anything to do with any God being angry on her because she is just a kid and she didn't do a thing wrong to deserve punishment as that...more like stupid adult's tongue that didn't think before saying something in order to be "polite". I manage to calm her down in end but anger in me sadly didn't vanish and I'm still pretty pissed as cougar on those ladies for what they said.
So either my idea of what is polite and acceptable to say is totally wrong or world seriously have very messed up way of saying/explaining things in what they consider "polite" in here.