There’s something a little unusual these days in having a teenager and a toddler at the same time. When Teresa was born, none of Caroline’s sixth-grade classmates were getting new siblings. She remains, to the best of my knowledge, the only eighth-grader in her class with a 2-year-old brother or sister. But I think this family arrangement is good for them both. Sure, 2-year-olds and 14-year-olds are in similar developmental phases, both trying to separate from their parents, testing how much independence they really have and focusing on their own needs as they try to create their individual identities. Yes, both try our patience from time to time. They even try each other’s patience every now and then, with Caroline sure that Teresa gets away with a lot more than she did as a 2-year-old (definitely not so, especially since Caroline had two doting grandparents in the house) and Caroline sometimes thinking we’re not taking good enough care of her baby sister (“Mom, she’s crying!”). Teresa, for her part, has to deal with someone who doesn’t want to play with her 24 hours a day. When she does play with her, though, Teresa eats it up. It was Caroline that introduced Teresa to “Beauty and the Beast” when the whole family was tired of watching Winnie the Pooh over and over and over again. It’s Caroline who takes Teresa into her room to play when I’m making dinner, and it’s Caroline who takes care of Teresa when we have to drive Frank to one activity or another and she just doesn’t need another trip in the car. Because of Teresa, Caroline has to come out of herself and care for someone else — someone else who thinks she’s the greatest thing since sliced bread, which makes it all a little easier. The quality of charity, or sharing kindness to someone without any expectation of having it paid back, is the theological virtue of caritas. So in a way, by snuggling in the recliner with her baby sister and watching the flatware dance, Caroline was sharing in the divinity of Jesus. Too often, teenagers don’t have the opportunity to do that anymore. They tend to try to isolate themselves from their families, communicating with friends on Skype and through text messages — media that keeps what they are saying well out of their parents’ earshot. Having a little one at home offers the teens a reason to dial it back, to stay home. They have a unique role to play in the lives of their baby brothers and sisters, and it’s different from the role they play with siblings who are closer in age. None of this is meant to discount the contributions of Frank, who also adores his baby sister and spends lots of time playing with and caring for her. But Frank, at 11, has not yet started to chafe at the family ties that teens find so annoying. What’s in it for Teresa? Another pair of arms to hold her, another pair of eyes to look after her and ears to listen to her, another heart to love her. And someone who will understand it all when Teresa hits her own teenage years.