(Contains Heavy Spoilers)
Adults:
Duke Matthew Bigcoc - Adam's Father
Rosalind Stewart - Matthew's 1st Wife
Elizabeth Bigcoc (Booty) - Matthew's 2nd Wife, Adam's biological mother
Isabella Heart - Matthew's 3rd Wife
Children:
1) Serena Stewart- Rosalind's 1st child
2) Luna Stewart- Rosalind's 2nd child
3) Ulena Stewart- Rosalind's 3rd child
Pam Stewart- Rosalind's 1st adopted child
4) Siliana Stewart- Rosalind's 2nd adopted child
5) Adam Bigcoc- Elizabeth's 1st child (Magical surrogate Child, True Biological mother: Isabella Heart)
6) Emma Bigcoc- Elizabeth's 2nd Child
Raphalia Heart - Isabella's 1st child
7) Sadina Heart- Isabella's 2nd child
Pomeria Heart - Isabella's 1st adopted child
Suna Heart - Isabella's 2nd adopted child
8) Ophelia Heart- Isabella's 3rd adopted child
In terms of age (from the eldest to the youngest): Raphalia, Pomeria, Serena, Luna, Adam, Siliana, Suna, Sadina, Emma, Ulena, Pam, Ophelia.
As of chapter 110, only the numbered children are recognized by Matthew, and therefore considered a part of the main Bigcoc mansion. Other children have little to do with Matthew, and thus have hidden identities.
Other relations:
Duke Hormon Al Stewart - Rosalind's father
Duchess Lippes Stewart - Rosalind's mother
Baron Kurvee Booty - Elizabeth's father
Baroness Finessia Booty- Elizabeth's mother
Rodeo Booty- Elizabeth's older brother
Sheona Booty - Elizabeth's younger sister
Tempo Booty - Elizabeth's younger brother
King Charlie Shepherd AbsoluteHeart- Isabella's father (Royalty)
Queen Eleanour Shepherd MightyLionheart- Isabella's mother (Royalty)
Note: Some terms like half sister and cousin, step sister and adopted sister have been used interchangeably (done on purpose).
Due to heavy timeline divergences, names and surnames are subject to abrupt change.