Q: We have an eight-year-old biological child and a six-month-old we adopted as a newborn. Our younger son has several biological siblings—and I’m wondering how to explain this to my older son. He’s quite sensitive, and takes his job as a big brother very seriously. I don’t want him to feel less important because there are other children who are biologically related to his brother.

A: A given in adoption is that our family grows, and not just with the addition of a child. Your son will come to understand, as you have, that terms like mother and brother can mean more than one person or more than the mother and brother in your house. I wouldn’t wait any longer to tell him, though.

You could say, “You are such a terrific brother! I wanted to be sure that you understand that your little brother is like your friend/cousin, Jimmy—he has some brothers who live with him and some who don’t. Your little brother has other siblings, too. They can’t all live together, but they will be special to each other as he gets older. He will always live with us, of course, and will always be our son and your brother.” Show him photos, if you have any, to make the topic concrete, and reinforce that it can be openly discussed.