Kids grow up fast. One day, they’re cooing in your arms. The next, they’re prepping for prom and arguing curfew.Time really flies when you’re having fun at North Center’s just-opened Family Grounds Cafe. Husband and wife John and Brady TenBrink transformed an auto body garage into the cheerful, 3,000-square-foot coffee shop and play space.Chill in the cafe with java, sandwiches, and salads. An adjoining room (accessible for a fee) has a playhouse and market, an infant-only crawl zone, and toys galore. Spontaneous live music and finger-painting sessions ensure Junior gets tuckered out by nap time.That never gets old.Family Grounds Cafe, 3652 North Lincoln Avenue, at West Patterson Avenue, North Center (773-281-0785 or familygroundscafe.com).Photo: Courtesy of Family Grounds CafeBUYBoujie Baby Couture Prima Collection Trunk ShowWhat: Score 20 percent off the Chicago designer’s stylish and supple leather diaper bags.Why: The hobo’s great for travel — even if baby’s not on board.When: Fri., 10 a.m.-7 p.m.; Sat., 10 a.m.-6 p.m.Where: Krista K Maternity + Baby, 3530 N. Southport Ave., at W Cornelia Ave. (773-248-4477).SEEThe Jolly Rogers HalloweenWhat: A crew of singing pirates stages a rollicking, interactive theater spectacle, followed by ghostly games.Why: Little landlubbers are welcome to go in costume.When: Sat.-Oct. 31. Schedule online at emeraldcitytheatre.com.Where: Emerald City Theatre, at Apollo Theater, 2540 N. Lincoln Ave., at W. Wrightwood Ave. Tickets online at ticketmaster.com or call 773-935-6100.DO18th Annual Harvest FestivalWhat: Compete in a scarecrow-building contest and listen to live music and storytelling at the free fall fling.Why: Leaf your worries behind.When: Sat. & Sun., 10 a.m.-3 p.m.Where: North Park Village Nature Center, 5801 N. Pulaski Rd. (312-744-5472).