Is it normal for my mother to constantly blame other people for her mistakes?

She's always claiming to be right, but half the time, the other party had the right idea all along and she ignored them for some reason. Then, when she ends up shooting herself in the foot, she claims that the other person's idea was her own and it was her taking another person's advice that led to her screwing up. The most outrageous example of her blaming others was that once, when one of the cats approached her in the kitchen, she started flapping her arms and screaming at it. This caused her to knock over a glass of chocolate milk, and she blamed the cat for 'making her do it'. She then left the cat outside in the snow that night.