Need some serious gender I.D. mojo for Wyndottes and Lavendar Amerucanas~

[Leavingegypt]

I have really wanted a BLRW, but all the breeders were too far away. Today I found a listing for a breeder who has some that are 2wks. old. She has not sexed them and after 2 of my BO ended up roos- I am full up on cockerels. Is there any wisdom you can pass on in picking out my chicks to up my pullet odds? She also has Lav. Amerucanas that I am interested in too.