http://lancasteronline.com/news/loca...a4bcf6878.html
The OP's state is one where there is no minimum age set. They do consider it on a case by case basis - especially if the parent has other issues as this article states. While I do think the OP's friend is WRONG to leave her kids home alone - if she is in fact doing so, it may not be the "slam dunk" many think it is.