Can't really tell their age by laying eggs or not. It is different in tanks, but in the wild the un-sexed "juvis" could go years before it is their time to move up in the pecking order.
My pair of Clarkiis started spawning after I had them for about 9 months ( not sure how long they had been at the LFS ), where as my pink skunk pair has been with me for 2+ years, and I am still waiting.