As we go throughout life, talking and interacting with people, we have two choices: 1) We can tear them down, or 2) we can build them up.
I've used Ephesians 4:29 many times to discuss this topic of building up/tearing down with children. I told them when they said hurtful things to people, it was like tearing down a house with a bulldozer. On the flip side, when they said encouraging, grace-filled things to people, it was like they had a hammer and nails, and they were building a house. Which one sounds better for people: tearing them down with a bulldozer or building them up with a hammer and nails? I could often be heard saying, "Please put your bulldozer away and get out your hammer and nails."
Ephesians wasn't just written for children. It was written for all of us, and it's a great place to start when considering how to encourage divorced kids.
One Sunday when I was in high school, I was at church with my youth group preparing for Youth Sunday (one of the best Sundays invented in Baptist churches, haha). I was lying on the floor working on something. I'm not sure what prompted the question, but I looked up at one of the sweet youth volunteers and asked, "Since my mom hates my dad, and I look like my dad, do you think she's reminded of him when she looks and me, and it upsets her?" She answered wisely, "When she looks at you, I'm sure she's reminded of the good things about your dad, and she sees those things in you."
Please don't think my mom ever said she hated my dad. She never spoke negatively about him. That was her policy, and she stuck to it. I think somewhere in my mind, I determined my parents hated each other because they weren't married any more. I guess I thought the only alternative to married love was hate. I'm glad I was wrong!
The youth volunteer who encouraged me hit on something important. She mentioned that my mom saw the good qualities about my dad in me. This is where I'd like to exhort you to encourage divorced kids.
When talking to them, you have options. You could speak negatively about their parents, or you could find positive qualities about their parents that you can encourage them in. Example: "Sarah, I love the way you serve your younger brother. I think you get your compassionate spirit from your dad. He is kind hearted and always considers the needs of others."
Remember to keep your bulldozers parked when you're talking with divorced kids (or anyone for that matter!). If you say negative things about their parents, they tend to internalize them. They're a part of their parents, so they may think you see those negative things in them as well (even if you don't).
Pull out your hammer and nails. Build these kids up as much as you can. Encourage the areas where you see God at work in them, and look for opportunities to say kind things about their parents. Your kind words will go a long way.