Maybe I can help.
The Swiss Travel System (STS) website uses the word "Ticket" in both the English and German versions of the site to refer to what we would call a Swiss Pass or Swiss Card. ( The French version uses the word "Billet" which means "ticket" in French but is different from what SBB calls point-to-point tickets. The German version of SBB will sell you a Billett (2 T's).
Look at this Swiss Travel System page where they list the "tickets" they sell:
http://www.swisstravelsystem.com/de/home/tickets-de/ticketuebersicht.html
Note that is it only passes and cards, no point-tp-point tickets at all. These are all passes and cards available to foreigners only, not Swiss---the Swiss Pass, Flex Pass, Transfer Ticket, Swiss Card, Half-Fare Card, and ( free) Family Card. These are no p2p tickets sold by the Swiss Travel System website.
For those, you go to SBB.
The Swiss nationals have their own array of price reductions, which are sold on the SBB website. These are called "abos", short for Abonnement or reduction. Most common is their one-year Half Fare Card.
The Swiss cannot get a free FamilynCard with any of their Abos. Instead, they pay 30 CHF for a Junior Card which is valid for one year. It allows a child age 6 to 16 to travel for free with a parent regardless whether the parent is traveling on a full price p2p ticket or with an Abo ticket. Each child In the family must have his or her own Junior Card, although the cards are free after the first two.
This is different from the STS Family Card, on which all children in the family are listed on a single card. (We have used these so I am familiar with how they work).
In short, the Junior Card and Family Card are not exact equivalents. The former can be used when parents are traveling on p2p tickets; the latter cannot.
This makes sense if you consider that the Family Card is a Swiss Travel System product. It is designed strictly for use with the Swiss passes and cards sold by STS to foreigners. These are (somewhat confusingly) called "tickets" on the STS website, but they are not p2p tickets at all.
Bottom line: the Family Card cannot be used for free travel when the parents are using p2p tickets. But while the Swiss cannot get a Family Card, foreigners can buy a Junior Card. So families traveling in Switzerland without passes can still get free travel for their children.