I think it's considered a year old, but my girls don't seem to change much after 6 months, but the roos change for a long time. Look at these two photos of my main roo (only roo right now).
At seven months
At one year
Twin Oaks Ranch Silkies
I can't believe those little Silkies grabbed my heart!

I have a wonderful DH who's a silkie enabler! 
Member of American Silkie Bantam Club!
Twin Oaks Ranch Silkies
I can't believe those little Silkies grabbed my heart!

I have a wonderful DH who's a silkie enabler! 
Member of American Silkie Bantam Club!























