One of Laufilitonga's wife was Halaevalu, the half sister of Taufa'ahau Tupou I and their children were the twins, Kalaniuvalu and Lavinia Veiongo. The line of the Kalaniuvalu still stands today and the descendents of Lavinia includes the Kupu family.
The first Kalaniuvalu had a son named Siaosi Pangia who had no legitimate heir, but his descendents are in Lapaha. The current holder of the Kalaniuvalu line however, is from the sister of Pangia named Afa.
Laufilitonga as you well know, preserved the traditional kava of the Tu'i Tonga by giving his kava to the Catholic Bishop. When Laufilitonga accepted baptism thru the Catholic Church, he realized at the same time that he will be the last king of his long dynasty, because Taufa'ahau has became sole ruler of the Tongan Islands. Everything that pertain to the Tu'i Tonga was to go to the Tu'i Kanokupolu, with that in mind, Laufilitonga decided that he will saveguard his position in the Kava or his kava in the care of the Catholic Church. Pea ne foaki leva 'ene kava ki he 'Epikopo! That is why a Catholic priest has the first cup of kava when he partake in a kava ceremony, even if the nobles are presents.
Today in the City of Lapaha, a "pongipongi" will be given once a priest has been ordained. This "pongipongi" of the priest is also a symbolic commemoration of his kava, given to the Church by the late King Laufilitonga.
For his heart, truly the mountain of this small Tongan, would not allow him to succumb easily.
Olaf Ruhen, author of Minerva Reef, on Finau Laione.