How can I help my friend?

These are tough, and I am glad that you recognize that you can't always believe everything you read.

That being said, can you talk to the person who posted this, e. g. in some sort of a private message? Ask - are you all right? That is a very safe question. And then they can tell you, oh, it's nothing, I was kidding around (possible, although people do often cover these things up), or I'm really scared or something in between.

As for what to do afterwards, that depends upon the answer, of course. You can provide the #s of shelters if you really think things are terrible, but understand that that is a huge step and can terrify a lot of people, even more than abuse, I hate to say. Many people are so frightened of changing the status quo that they won't help themselves and get out of a bad situation.

Plus you may not know the specifics. There is a big difference between an 18-year-old and a 13-year-old in terms of their options. One generally good piece of advice is to encourage people to tell a trusted adult. Someone in the area is usually going to be a lot more familiar with the truth of the situation and able to provide more immediate assistance. It is kind of you to care but these things can be blown out of proportion, plus you can find yourself making it harder for people, if you are too pushy or are making it to be more of a big deal than they think (or want to believe) that it is.