Hi @Mysg
Thank you for the request.
Yes, it is possible to buy the Junior Card before the trip.
Please note, however, that if the trip cannot be made due to the Corona, there is no refund possible for saver tickets.
However, we do have offers for tourists. With an offer of Swiss Travel System, are the Swiss Family Card free of charge.
You can find all the information here:
https://www.sbb.ch/en/help-and-contact/produkte-services/offers-for-tourists.html
I wish you Happy Holidays.
Best regards
NicolasK