Hi AlexanderD22,
There's no problem TAF'ing a family member or partner. The only thing I would suggest you do however is drop a ticket to support as soon as your friend signs up, mention both your and their PokerStrategy name and explain the relationship etc.
You will both need to send ID docs through to ensure that you are different people of course (you won't need to again, if already completed, but your friend will need to). If you can have these to hand ready too that would be useful.
Email for ID docs:
security@pokerstrategy.com
There shouldn't be a problem, it's just customer support are quick to deactivate duplicate accounts on the same IP address. If you pre-warn them that they are a different person and promptly send in the ID, this shouldn't happen to you.
Best regards,
Bart