My wife is a bit of a bully, and she’s aggressive with our children. I don’t like it, and don’t know how to stop it.
You need to talk to your wife, and try to create a parenting style that works for both of you, that you both agree with. Help her out with the children more, because a lot of it could be due to stress. Communicate, and figure out where the aggression is coming from, and what you can both do to minimize it.