On Paddys Day the city will be very busy! Family friendly for the parades in the am-midday but after it will start to get ‘livlier’ They would definitely want to book some place for grub. Depends what their budget is. Laylas or Sophies would both be cool venues and they do a set menu option. But may be too much for the teens €wise. Nandos/ milanos/captain Americas/ gotham cafe/ carluccios are simpler style. Do you know where they will be staying? Or what their itinerary looks like?