Code:
character_record		Cassius Brutus, 	male, command 0, influence 0, management 0, subterfuge 0, age 14, alive, never_a_leader
character_record		Titus Brutus, 	male, command 0, influence 0, management 0, subterfuge 0, age 10, alive, never_a_leader
character_record		Cornelius Brutus, 	male, command 0, influence 0, management 0, subterfuge 0, age 7, alive, never_a_leader
character_record		Oppius Brutus, 	male, command 0, influence 0, management 0, subterfuge 0, age 3, alive, never_a_leader
character_record		Galla, 	female, command 0, influence 0, management 0, subterfuge 0, age 50, alive, never_a_leader
character_record		Hostia, 	female, command 0, influence 0, management 0, subterfuge 0, age 30, alive, never_a_leader
character_record		Lucilla, 	female, command 0, influence 0, management 0, subterfuge 0, age 28, alive, never_a_leader
character_record		Paulina, 	female, command 0, influence 0, management 0, subterfuge 0, age 12, alive, never_a_leader

relative 	Tiberius Brutus, 	Galla,		Aulus Brutus,	Amulius Brutus,	Vibius Brutus,	end
relative 	Aulus Brutus, 	Hostia,		Paulina,	Titus Brutus,	Oppius Brutus,	end
relative 	Amulius Brutus, 	Lucilla,		Cassius Brutus,	Cornelius Brutus,	end
This is placed in descr_strat at the bottom of each faction' entry.
character_record as you see determines what family members are present at the start of the game (including childs). Relative section is who married with whom, and what children they have.
relative ...... father,.... wife, ..... children,.....
Be careful with age though - game doesnt like unrealistic values...