I believe you have to get to the heart of the complaining. Complaining doesn’t glorify God, it says that He is making mistakes, has overlooked our needs, or has burdened us somehow. Whining children are disobedient and complaining parents are just as disobedient. I believe that we must learn what true obedience is, as parents first, and show our children what obedience is as well. I’ve mentioned Doorposts bible studies before, and there is a wonderful 30 days “boot camp” for parents (there are activities you can do with your children) that really teach the heart of why we are obedient to God and how to teach our children to be obedient. It has helped me really reign in some of those undesirable behaviors in myself and in my children. We have to get into the Word and get to the heart of the issues we face if we want them remedied.