It’s not about being their therapist I think she had a mental break down, I’ve seen this a few times in public and in workplaces/schools. People suddenly starting crying or pouring out some horrible things they’re going through and you don’t even know them. I think it is because they don’t have anyone to share their difficulties with.Those people lack boundaries. It’s a huge red flag. It’s not your job to be their therapist.
Being kind is not that hard, just listening to their story can help, you don’t have to counsel them if you can’t think of the right words.