You may purchase a second class pass regardless of age. Add up fares for your itinerary to see if a railpass will save you money. Second Class Second Class Saver 5 consec. Bonuses require use of a travel day on Flexipasses. Saverpasses are for 2 or more people traveling together at all times.
All Swiss passes are also available in major train stations.
Kids under 16 travel free with a parent using a Swiss Family Card, other kids 6-15 half fare, under 6 free. The Swiss Family Card allows children under 16 to travel free with their parents. Based on the validity of the parent's ticket or pass, this works even on the high mountain routes. Geneva to Brig. These discounts do use a travel day on a Swiss pass.