More lore below

All I'd say is that if Thanksgiving happened it'd be utter chaos...

Some who married in kept their names but there are others such as Himeno who took up the Watanabe title or are known only via their married surnames.

Some stuff

-Marah and Kapri are half Karmanian via their father, the show never established their relations really. Karmanians are aliens from the show but I'm elaborating more on them(will make a lore post about them). Their physiology overlaps organic ones so the sisters, while having a mother, are barely related to her. Kairi Watanabe was adopted when Kiya and Kanoi were around four years old.

-Mia and Terry are third cousins once removed via Cam, born around the same time as he was(let's joke around about how some could see him as their nephew). Their mother is Mia's Shinkenger counterpart via this AU.

-While both families exist Cam and the sisters are pretty much unaware of the main one due to specific reasons.