The issue comes when someone has 3 plus children where do you draw the line? On the face of it being allowed to guest two children to the lounge during school holiday sounds great but do step children count what about adopted or fostered children it becomes really messy and in todays world it is just asking for trouble. Leave the rules as they are. There are plenty of restaurants at Heathrow where you can have drinks and something to eat pre flight without having to fork out for a Club ticket.