One thing I'd add to the advice above is don't deny to your children that mommy has a problem if it comes up. They know and are looking to you to protect them but that also includes acknowledging to them what they see with their own eyes. Saying anything that downplays the problem has a good intention behind it but teaches your children to not believe what they see and hear. That can eventually cause them, as adults, to not trust their own judgement.
Best of luck and I hope your wife chooses to do what's necessary to overcome her problem.