Morino Evolution?

I have a Morino tamagotchi that I bought recently (brand new, e-bay), and it will not evolve past child stage. It is now 7 years old, and has yet to become a cocoon. It is healthy, well cared for, and has not been paused at all. Its weight is at the minimum, and it has not been hurt by any predators.

Does anyone know why it will not evolve? This can't be normal.

Am I doing anything wrong? I have been running it off my experience with other tamagotchi, as I can not read the Japenese instructions.

Any help or advice would be much appreciated.

I have one too. It's still not at that stage, so I am not sure. I pause it a lot too.