I wouldn't report her over her house getting messier or forgetting to bring afternoon tea a few times.
If it were one of my friends in that position, I'd go over and help clean up, get DP to watch her children, and have a few wines and see what is going on. If she didn't already have support for her mental health issues and self harming etc, I'd help her get in touch with somebody.
Obviously if things get worse and the children are in danger, then you have to report. My first steps would being trying to help out first though.