They rebuilt Ralph Walker Ice rink on upper State Street with kids’ programs- use the Skate New Haven website. Near that is a new Food Hall if you need lunch; Shoreline Trolley Museums does December weekend trolley rides; If you need cold/indoor stuff if they’d like to see Christmas scenes exhibits go to the Father McGivney Center (formerly KofC museum); if they like city drawings you could quickly stop in to the new Hill Museum run by the artist himself; for a junk food snack they can eat fried dough etc at the new Fest Faves place. Also, remember the Barnes and Noble downtown has a kids corner area and I think still a snack place inside. If you do do an East Rock hike you can entice them by using the “secret” Giant Steps….