Genesis 11:27-23:20 (Specifically 11:30, 16:1-6, 21:6)
Sarai was the wife of Abram that God promised to make a great nation. One of the first things the Bible tells us about Sarai is that she couldn't have children (Genesis 11:30). Now in today's world that is sad but in Sarai's time they would have believed she was cursed! That means a lot of people would not have wanted to be her friend or be around her. It was probably lonely and definitely made her sad.
Well one day Sarai decided to fix this problem so, in keeping with the custom of the times, she convinced her husband to make her maid his wife too. And since Hagar was basically a slave, the child would be considered Sarai's and she would finally have a child. Now Sarai's plan worked and Hagar got pregnant but then Sarai and Hagar weren't getting along. Then Sarai was mean to Hagar.
Sarai made some bad choices. Having a baby through Hagar wasn't God's plan, but she was too impatient to wait. It is never right to be mean to someone and she was mean to Hagar. However, God didn't give up on Sarai. He had a plan and eventually (when she was 90) she got her very own son, Isaac. When he was born she said that God had made her laugh or made her happy. We need to learn from Sarai and trust in God's plan.
That it will all be for the best in the end, just be patient!
Collect some baby pictures of your child (or children) and talk about what a wonderful exciting time that was for your family and how happy God made you. If you had a hard time having children, talk about how God brought you through that time of waiting.