Hello AkhilSabu
Firstly, welcome to the SBB Community. We are a customer support forum run by volunteers.
The Swiss Family Card works for parents, only.
If someone else wants to take advantage of Swiss Family Card benefits, they have to purchase the Children’s Co-Travelcard.
https://sbb-tickets.cc/en/tickets-offers/travelcards/children/children-co-travelcard.html
This card offers the same advantages as the Swiss Family Card, yet is, for tourists, only available on-site at a railway ticket office. For tourists, it comes as a paper ticket. The cost is CHF 30, and it is valid for 1 year. Only the registered person can use it together with a child, whose name must be registered in advance as well.
Kind regards,
Roland