Yeah, I'd give them a little longer to fill out before deciding fully then! If it helps, here is the Ameraucana club page that has pictures of Lavenders (they are called 'Self Blue' in the standard) for you to compare to. You can look at some of the other varieties for example of their shape and what the comb should look like as well, and obviously at the Self Blues for feather color.
http://ameraucanabreedersclub.org/gallery.html
The written standard is here as well (though I find pictures a lot easier to wrap my head around personally) : http://ameraucanabreedersclub.org/standard.html
http://ameraucanabreedersclub.org/gallery.html
The written standard is here as well (though I find pictures a lot easier to wrap my head around personally) : http://ameraucanabreedersclub.org/standard.html