Mystery chick, gender and breed?

[FattyChickens]

Was told it was "a gold star" but I don't know :/ his/her tail is growing in miraculously slowly and is much much smaller than the 4 other chicks I got at the exact same time. I know there are late bloomers.. but they are all 7 weeks old and this one is half the size of the others.
According to Google images, if it's a red sex link, then his coloration means roo. Help

 

[FattyChickens]

Sorry here are the images

 

[GirlsHuntToo]

It's a pullet!

 

[SilverBirds]

Comb says pullet, but there is more white than most RSL females have. Might just be the cross.