[kyrilliondaemon]

I don't breed, but hamsters can be paired at any age - it just gets more difficult to pair two adults than to pair two pups or an adult and a pup. Our pairs/groups are all same sex, but we temporarily paired an eighteen month roborovski with a four month roborovski a while back, it lasted about two months before the younger ham realised it was in the middle of puberty and decided to be a pest lol
Our current pair is a father-son pair who were introduced when the son was four weeks old, and our trio are sisters but thats just when its easier. Introducing hams for breeding is best done when the hamsters are ready to breed and that depends partially on age and partially on the hamsters.

I mean this in the best of possible ways, but it'd look a lot better if you researched this yourself rather than having to come and ask. I find it a bit worrying when someone who plans on breeding doesn't know about the risks of a ham getting pregnant too young (or too old).