Family account - I need rom for 1 more

My wife and I have 5 children. The family account is limited to 6 people. Is there a way by which Apple allows for more than 6 people to share? It seems like the limit of 6 is a bit arbitrary, although likely to prevent abuse of the system. Notwithstanding, 5 kids all born to the same parents (kind of irrelevant) should be able to share our music and apps etc... Help please!