I would report her to someone for the sake of the children they need to be looked after not ignored/neglected/left to fend for themselves at that young age. Its not right.

Something bad could happen to the children and you would never forgive yourself. They cant phone and report her themselves they need an adult to do so and if a member of the family cant see then and you can then great !

Do the reporting....

You may/will lose a friend but would of helped two young children.