Having your wife on the discipline train is a must, so it's good that she's with you on that. You're just gonna have to get tough, but have a plan and share it with your wife BEFORE you put the plan in action. Your girl may be 9, but that's not too old yet for her to come around to you. However, if you are letting her walk all over you and get away with things now it'll just get worse.

Spare the rod, spoil the child.

Jesus... I hope you know Him personally like I do.

Si vis pacem, para bellum.

Proud crossbow hunter!