I wanted to point out that even though the Nanny's statement is damning. Her statements are directed towards Anna and not Stern. Now that Anna is dead then the Bahama officials may not think that the baby is in harms way under Stern's care. Basically there is no proof that Stern is mistreating the baby at this point and until there is the baby will have to stay with Stern until the Bahama courts order a DNA test done on the baby. (if that happens)
Except... if Stern thought or was aware she was underfeeding the baby it was on him to do something about it.