ShiHan family: 
Han Geng, Siwon (adults). Donghae, Henry (brothers. 7 and 4) 

KangTeuk family: 
Leeteuk, Kangin (adults), Hyukjae, Kyuhyun (brothers. 8 and 5)

HeeMiBum family: 
Heechul, Zhou Mi, Kibum (adults), Ryeowook, Sungmin (brothers. 8 and 6) [note: yes, this is a strange 3 way family. HeeMi are the 'appa and baba' and Kibum is the 'uncle'.... but Heechul and Kibum have a .... thing. Because Heechul is a polygamous]. 

KhunToria Family: 
Victoria, Nichkhum (adults). Amber, Sulli, Krystal (kids. 3? i think. newborn twins) Luna might be one of their kids too... I'm not 100% because she only shows up pregnant so far. 

YeDong family. 
Shindong (adult), Yesung, Onew (brothers, 10 and 5.) 

I don't always maintain the s for them, obviously. I wanted Henry and Kyu younger than their actual to EunHae kids... but maintained it with Yesung and Onew... making Onew older than Henry and same age friends with Kyuhyun.. xD Whatever. It works for the story. 
 

**I have added the people the chapters are mainly about in the chapter. Kyuhyun means it's mostly about him. EunHaeRy means it's mostly about Hyukjae, Donghae and Henry. Make sense? ^^***