Originally Posted by remdk

batmandds welcome to the QR forum. You will find the dashboard a great help in getting answers rapidly.

Access to Al Safwa lounge is for holders of QR or OW first class boarding passes only. No guests are allowed. But you should be able to use the First Class lounge and invite guests. Regarding guests in the First class lounge, much depends upon your OW status since the lounge is primarily aimed at OWEs. Al Safwa has a much, much higher standard than the First class lounge.
If you are thinking that the two adults would travel in F and the two children in Y then you can almost certainly forget it! It is very unlikely that QR would permit two unaccompanied seven year old children to travel alone!