Nothing much to add really to what's been said before - all of which I agree with. I suppose though that the original commenter might not have realised this was a child's work - how many of us check the artist's bio before commenting? Actually, if done with MS Paint I think the image shows quite amazing skill and perseverance - she mustn't give up!

Dinhi, it's probably best (though I'm sure you have already) to warn your daughter that just as in the real world most people here are perfectly pleasant and some can be really very nice - but that some aren't, and a few can be downright nasty. She may have encountered one of them, or as said earlier, someone who was having a really bad day. We all get those and it's all too easy to say something on the spur of the moment that we regret later.

Steve