Parents aren't ever ideal either

If she asked me, not that she did, I would've told her that no, siblings don't suck. Bad parenting sucks. She's blaming her brother for having been a victim of her parents not knowing how to deal with him acting out or having ADHD or having whatever else impairments that make his transition into society difficult.

Who knows? Maybe his learning disabilities, being disabilities, make her parents feel bad whenever they resent him for not being easy to raise. So they dismiss his antics as symptoms of his condition, and explain his behaviour away, all the while hesitant in sticking him in a structured environment to teach him that his actions have consequences, learning disability or no. They give up on him ever amounting to anything of himself, and push the responsibility of checking off the boxes for the minimal prerequisites to being a functioning adult on her, and she's pissed.

Of course she's pissed. It's totally unfair, and she had to learn the hard way that her actions have consequences, and be the good girl, while growing up beside exhibit A of how people will bend over backwards for you even if you don't deserve it. Even if you're only taking advantage of the leeway people give you. And being the good girl, her only reward is to have to manage her brother's schoolwork, with no benefit to him or herself.

But he does not, by himself, make up this exhibit of corruption. Nor, are her parents really to blame, because they were probably unequipped to raise a child not of the norm. But, well, being unequipped to dealing with difficult and less than ideal children, you probably shouldn't have kids. Kids aren't ideal no matter how they turn out. Also, being maladjusted and walking around blind to your own actions and the motivations behind them, you're also not exactly conducive to creating positive and healthy environments for your offspring.

Not to mention her own behaviour. She definitely shouldn't just roll over and take it, but passive-aggressively posting about it on tumblr doesn't exactly garner any actual change in her situation. It just allows her to ruminate in her resentment.

Again, she didn't ask for my advice, and I'm not exactly offering. I just want to get this off my chest.