1)You can have one non-immediate family member in addition to as many immediate family members as you want.
ICBC states the resctriction for N drivers is “Limit one passenger: 1 passenger only (immediate family exempt) unless with supervisor age 25+ with a valid Class 1, 2, 3, 4 or 5 licence.
If you have a fully licensed driver over the age of 25 in the car with you, then you can drive as many friends / non-family members as you can legally fit in your car.
2) that is up to the law enforcement officer on how they would like to confirm if the passenger is a member of your immediate family.
As set out in Motor Vehicle Act Regulations (MVA Regs), Division 30.01(1), an immediate family member includes a spouse, parent, grandparent, child, grandchild, sibling, step-parent, step-grandparent, step-child, step-grandchild, step-brother, step-sister, foster parent, foster grandparent, foster child, foster grandchild, foster brother or foster sister.
Immediate family members do not include cousins, nieces, nephews, aunts, uncles and so on, as they are not listed in the immediate family definition.