How to make it grow older?

[I_heart_brian]

How do you make them grow older? There was a trick but I didn't understand it. Anybody have any suggestions?

 

[Mistrunner]

Why not just wait and let them grow naturally? Seems rather cruel to make them grow up really fast.

 

[I_heart_brian]

well me and my friend are trying to get ours to mate and i paused mine for a day and it's still 5 and hers is 6. I want mine to be 6... so yea.