As others stated, she thinks she is dominant over your wife and children, this needs to change. The most important thing is consistency, you, your wife and your children must be consistent and send consistent messages.
She needs to earn everything she gets and learn that your wife and kids are in control. Before she gets a snack, a toy, a meal or attention she must earn it. A simple sit, stay, wait, down, whatever she learns she must perform before she gets anything.
When you go out the door she goes last, wife and kids go first. If there are rules, such as off the furniture or areas she is not allowed it must be consistently enforced. It is a process that can take several months but it works.
Also, you start and stop play time, you control every aspect of it. If she doesn't behave or play correctly stop it and ignore her for a short period of time. Teach her how to take a time out. teach her to go and lay down somewhere when you want her to, again enforce it when needed.