What is my sweet Dumpling saying?

[chilman]

I have a buff silkie that is about 7 months old. Lately she has been making a strange noise. It sounds like she is rolling her tongue! My other female silkie does not make this noise. Any idea what she might be doing (other than making a noise) or what this could mean?

 

[ChickensAreSweet]

A trilling sound (purring) means they are very very happy.

Also there is the same sound that is used as a general alarm when they are outside.