I have seen it said in lots of places that tamas need to be at least 5 or 6 before they can mate.
I had 2 tamas (connection v2) that were good friends (4 faces) as teens. They were hatched at the same time and so were extremely close in age as well.
They were connected a lot.
As soon as they became adults the first connection caused them both to become partners (4 hearts)
After 24 hours as adults. They mated and had babies.
They were both 4, I can guarantee this as I couldn't believe what had just happened and checked their ages a number of times.