How and when do I tell my 4-year-old that her siblings have a different biological mother?

Q: Dear Rosie, I have a 4-year-old daughter with my current wife and three teenage kids from my first marriage. For various reasons, my older kids’ mother hasn’t been in their lives. When do I tell my 4-year-old that her siblings have a different biological mom? And how do I tell her? —Mr. Mum

A: Dear Mr. Mum, As adults, we can complicate things with the emotions we have about a situation, especially when it’s about family. But it really isn’t necessary to bring those feelings into the conversation with your child. Explain the circumstances to your 4-year-old in a matter-of-fact, reassuring way, and do it soon—perhaps when you’re strolling through the park, giving her a bath, or having other unhurried, one-on-one time together. Start in neutral territory by talking about her mom, and all the wonderful things she does as a mother for all your kids. You can then introduce the fact that her sibs have another mom: a different one who carried them in her belly. Reinforce how lucky they are to have the mom they do know and love—her mom—in their lives. Your daughter may ask more then, or she might not have questions about her siblings’ birth mother until later; either way is fine. Be open and honest, but don’t confuse her with too many details if you have unsettled feelings about the situation.      However, reassure her that her mom isn’t going anywhere and loves being a mom to her and all her siblings. Life isn’t perfect, but with honesty and love, our children will grow to understand it.