Esther and her "patch of evil snakes."
Suppose you pick your daughters up for visitation one fine Sunday morning and they tell you "We don't want to go back to Grandma Jan's because she hurt Esther yesterday," and show you the long scrape on her arm that Jan put there Saturday.
A) Consider the fact that your mother's Bipolar Disorder is still unmedicated, that her psychiatrist has recommended she not be alone near your children, and that your own father (her husband) has warned you against her being near the kids too much, and decide that this really is the last straw and take them elsewhere...
B) Say "No, she didn't," even though there is physical evidence she did, and take them over to spend the day at her house.
By the way, Adult Protective Services, you are calling the wrong person if you want to know whether Jan is a danger to herself. I fucking hope she is, because it has become painfully obvious that her death is the only thing that is going to protect my children.