The Min Family
Parents
Yoonkook = Yoongi x Jungkook

Children
From Oldest to Youngest:
Nabi; Female: Oldest
Nabi as a baby

Nabi; When she's older

Siwon, Male: second oldest

Gwang-Jin, Male: second youngest

Minseok, Male: youngest aka the baby of the family

The Park-Im Family
Parents
Jimin x Jaebum

Children
From Oldest to Youngest:
Chittaphon, Male: Oldest

Jay, Male: Middle child

Luhan, Male: Youngest aka the baby of the family

The Jung Family
Parents
VHope = Hoseok x Taehyung

Children
From Oldest to Youngest:
Twins: Jun & Mason
Jun: Male (older than Mason by a minute)

Mason: Male (born a minute after Jun)

Mark, Male: The youngest aka the baby of the family

The Kim Family
Parents
NamJin = Namjoon x Seokjin

Children
From Oldest to Youngest:
Hwan, Male: Oldest

Haneul, Male: Middle Child

Nari, Female: Youngest aka the baby of the family

So that's the families.
The Jungs, the Kim's, the Park Ims and the Mins x