I have been in your situation quite a few times. Get your family organised, have all the boardng passes in the correct passport with yours on top and wait for group 2 to be called. All your family will be able to board with you.
Getting everyone through fast track security is more of an issue as they seem to have tightened up at T5 on allowing one guest only. Deciding who gets to go in the lounge as the guest can also be more tricky. Enjoy your trip.