Are my Silkies pure?

[Crazy for Chickens!]

They don't develop blue earlobes until they are older. Mine starting developing those at around 8 weeks.

 

[drumstick diva]

I thought you might be asking about ear lobes, I couldn't imagine where else they would be blue. Silkies could have other color or wrong comb etc. which means poor breeding but they could be pure bred silkies..

If your breeder shows her birds, I would imagine she would have all purebreds. She may or may not sell poorer quality as pets or cull them.