Speaking in wisdom (what Proverbs means by "opens her mouth with wisdom") means speaking what is appropriate and useful at the time. As James told us, wisdom manifests itself in many ways, including purity, peaceableness, reasonableness, and gentleness. It is sometimes hard to see how we can be such people while herding our children off to school on a Monday morning, but we can be such people. We can speak and act in wisdom. We can be direct without being unreasonable. We can be clear without being cruel.
Our homes often become so accustomed to our lack of wisdom that we think wisdom won't work at all. We think that the children will not move if we do not yell at them. And, in fact, we have usually created just that situation. If they are used to our yelling, they will actually wait for it before they move. We have created our own world of foolishness (the opposite of wisdom), in which our speech is negative and controlling and has nothing to do with wisdom at all.
Go back over your morning. Did you open your mouth with wisdom this morning? Did your children leave with yells ringing in their ears? Were your last words ones of encouragement? What about your husband? Did he leave with a reminder that you love him, or a reminder to get something on the way home at the store?
Did you open your mouth in wisdom this morning?