I've had student discount premium and I've got an invitation for premium family. But my bill was paid 3 days ago. How is it now with the payment Do I lose the already paid money? Because the owner of the family has to pay for me probably right now.
When you accep the invite to their plan, your remaining Premium time will be paused. The time you've paid for will be reinstated onto your account should you ever choose to leave their Premium for Family plan.