To the Mother Whose Daughter Pushed My Angel on the Playground

Yes, you there with a loose bun on your head happily chatting away with your friend. If you didn't care to noticed, I shouted twice, TWICE, for your daughter to stop pushing my daughter onto the ground. What's worse, as I was making my way to refrain her from further bullying my daughter, your little princess decided to pour sand onto my daughter's head. And what did you do? You pretend as if nothing happened, or that you were probably too engaged in your conversation to have noticed what your child has been doing - bullying.
From the language that you speak, I'm assuming you're French. Now whatever happened to French Children Don't Throw Food? Your daughter definitely do not fit the criteria of a French child, who according to the author is calm and well-behaved. Granted, not all french children are angels like what has been generalised in the book. No, in fact, your daughter may be an angel at home, but when outside, she is a bully. 
I've noticed since the moment you arrived at the playground. Your daughter kept wanting to play with my daughter, and she only wanted to play things her way. She's pushed my daughter around a few times, but I didn't react because they were all gentle pushes. However, I noticed that every push your daughter made, she would turn to your direction. And every time you turn, she would hug my daughter, as if they were the best of friends. How was I to tell you that your little angel has been pushing other kids around, when clearly she knows exactly what she's doing to manipulate the situation into her hands?
I wished I could have done more than just shouting "no pushing" and "please do not pour sand on other people's head". I wished I could have told you off for not having the decency to watch over your kid. But I didn't. I merely told my daughter to not let other people do that to her next time. I told her that not everyone in the world will be as nice as her mom and dad, and that she will have to accept that and learn how to defend herself. And I also told her never to push nor hit others while defending herself (unless we're talking about inappropriate male-female struggles, in which she should just go straight to the nuts). 
Why? Because I'm better than that. I'm teaching my daughter the cruel reality of life. But instead of dwelling on the negative, I've chosen to make a lesson out of it in hopes that it will make her into a better person, that she will know that it is not a nice feeling to be bullied and because she now knows how it feels to be on that end, that she will not do it to others. 
They say, bullies are bullies because they lack love and attention. I don't blame her, because for the whole two hours I was there with my daughter, you never once interacted with your daughter. You never once cared to sit facing the playground to pay attention to what she was doing. Heck, you had your back facing the playground the whole two hours I was there. Perhaps you're different at home, but your daughter's action says otherwise. 
To the mother who was too busy chatting with your friend and had your back to the playground, I sincerely hope that you will one day realised that parenting is much more than just feeding your daughter artificial food and letting her play freely at the playground. Parenting is about guiding your children and helping them learn right from wrong. It's not my responsibility to parent YOUR child, but I sincerely hope that one day you will realize that there is a need for improvement in your child's behavior and that you will help guide her into a much more pleasant and kind hearted human being.