MIL rude to granddaughter
My niece went over to her grandmother's house and came back crying after spending the night. She said Grandma yelled at her constantly for such things like sleeping on the flat sheet, drinking a glass of milk in a plastic cup rather than a glass, and changing the channel of the news station. I am sure she is telling the truth (she is ten) and I always sensed my mother does not like her. She favors the grandsons. She even threw a cheap barrette from the dollar store at my niece and said, Happy birthday, and laughed. How should I handle this?