Gender help!!!

[Ccdance75]

I am brand new to this. I feel like I've done so much research and still confused! If females have waddles and combs and can crow, how do I tell the difference?
I have four that I purchased from a farm, 8 weeks old, supposed to be all female. Then we acquired 11 newborns from my son's class. I have no idea what breed or sex. I don't want to mix them with the females (do I?). I DO NOT want fertilized eggs! I want to bring the two groups of chicken together soon. What should I do? How can I tell for sure?

Thank you chicken community!

 

[Rhodebar Lover]

They don't lay eggs until they are around five months old, so I wouldn't worry about fertilized eggs yet. Also, I would wait until they are similar in size to put them together because they will injure the younger chicks. When they are around six weeks old, you can post pictures to determine the gender.

 

[GitaBooks]

In general roosters develop red combs and wattles before 10 weeks and hens after 14 weeks. Hens rarely try to crow, they can make some of the silliest of sounds.

Roosters also develop saddle and sickle feathers (on the tail and back).