New here and need help aging my chicks!

Hello! I am new to this forum and am so thankful I found it! We have had hens and a rooster since last year but I finally broke down and decided to raise some chicks. We bought three chicks from a local farm supply store last week and the man working said he estimated the chicks to be three weeks old. After browsing this site for a few days, I have my doubts that they are that old. Maybe he meant three days? I'm not sure. I have added a picture of them last week.

Meet Ruby (RIR), Maya (SLW) and Daisy (BA)! Please let me know your opinions on their ages! Thanks so much in advance.

 

Thank you so much!! I think I'm going to love it here. I've been lurking for quite a while and enjoy it! We have had them for eight days and their wings aren't completely feathered yet and two of them have just developed tail feathers within the last few days. Fingers crossed that they're all pullets! Lol!

 

Daisy is our second BA and they are both such calm girls. I love all my chickens but Ethel and Daisy are definitely special. I'm a little worried about the SLW turning out to be a roo. I hope not though bc I don't think our Fred would be a fan.

 

I have a friend with a large farm not far from us who we got three of our hens from and some of our rabbits. She will take the rooster for us if needed but fingers crossed it's a she. We're definitely already attached to the little gal/guy.

 

That would be terrible! do you have trouble with them since there is more than one roo?