Today’s my husband’s birthday, and we’ll celebrate tonight with birthday cake and cards. But this morning, other than a quick “Happy Birthday” before I left the house, it was a normal morning: everybody up around 6 a.m., Caroline and I out the door before 7, to be followed by Frank leaving for school by 7:30. Tony and Teresa are the last to leave. That’s not the way birthday mornings usually go in our house. Usually, we have to sing happy birthday and eat cake for breakfast, starting out the day on a sugar high. OK, it might not be the healthiest habit in the world, but it was ours. But now that we have three kids in three different schools, not to mention sports and theater and other activities, not to mention two jobs, time is at a premium, and especially time when we are all home together. Indeed, having two adolescents and a preschooler at the same time leads to a somewhat dissonant family life. We have Teresa, who is with us unless we are at work and she is at the sitter or at school. Then we have Caroline and Frank, who leave us in the morning and don’t return until dinnertime, or later. And when they are home, they spend much of their time in their rooms, doing homework and communicating with their friends. When they want to talk to us, it’s often late at night — teenager hours, coming fully awake not until well after the sun goes down. But Teresa is still up with or before the dawn. There’s nothing very remarkable in any of that; a 3-year-old needs to be with her parents, and teenagers need to establish their own lives and identities. What is remarkable is what happens when they come out of their rooms, and play. Caroline spent some time chasing Teresa around the living room last night, not long and not doing anything special, but Teresa was delighted, laughing and jumping on and off the couch. The beautiful thing was watching Caroline laugh along with her. It’s the same when Teresa plays with Frank; she lights up when her brother and sister want to spend time with her, and it’s as though I can see their younger selves come out to play. Families are important in so many ways. Each family is different, but ideally, they all help children grow up knowing they are loved and learning how to love other people as well. When Teresa was smaller, I used to joke that every baby should come with a teenager in the house: it makes it much easier to run out to the store or pick up another child, when you don’t always have to bundle the baby up and deal with the car seat. Now I’d say that every teenager should come with a small child — toddler or preschooler — in the house. They remind everyone, parents and teens included, that sometimes all you need to be happy is someone to make you jump around the living room. Or someone who always wants to help blow out the birthday candles.