Thank you for your request.
The Swiss Travel Pass gives you free travel on trains, buses and boats in Switzerland. You benefit from free use in over 90 Swiss cities.
In addition, you benefit from free admission to over 500 museums and discounts on mountain excursions. Prices and information on the Swiss Travel Pass and Swiss Travel Pass flex offers can be found here: https://www.sbb.ch/en/leisure-holidays/inspiration/international-guests/swiss-travel-pass.html
Because you are traveling as a family, then this offer is worth it for you. You have the possibility to get the Swiss Family Card. Children between 6 - 16 years travel with their parents through Switzerland for free with this offer, as long as the parents have a Swiss Travel Pass. You can find this information here: https://www.myswitzerland.com/en-ch/planning/transport-accommodation/tickets-public-transport/swiss-family-card/
Children up to 5.99 years travel free in Switzerland.
I wish you a good day.