Upcoming The Sims 4 expansion Growing Together adds a multitude of family interactions, new systems called milestones and social compatibility, as well as infant Sims.
Don’t fear, as infants will arrive for all players in a base game update. They will have a wide variety of clothing, hairstyles, accessories, quirks, and special interactions. You can purchase and use infant-focused furniture like a changing station or a playmat. Adult sims can also carry their infant children around the world in a special backpack.
A variety of new interactions have also been added. Elders can now interact with children, including their grandkids, in new ways. Toddlers, just like infants, are also receiving new quirks like Picky Eater or Early Riser. Children have four new aspirations: Slumber Party Animal, Mind and Body, Playtime Captain, and Creative Genius.