Yeah im totally attached to my little one. Even if its a roo i don't think i can let it go. Keep trying to introduce go to the other chickens to help it socialise but its taking time and caution.
Blt79, i don't know much but i have been reading a lot of posts lately no this website. At 3 weeks its a little early to sex your chicks. Some breeds can be sexed by their feathers. I don't know which breeds these are but you could look, although since yours are mixed it may not work. Roos supposedly have thicker legs, feather slower, and get pink in their comb much sooner. Roos also gets wattles earlier. Although some people say you can't reply on these tips, sometimes a pullet can show the samesigns. However, i would say a very red and growing quickly comb before 6 weeks is definitely a roo. From what i can red yours are as feathered as mine was at 3 weeks if not more, but i see yellow combs.
Hope this helps, this is just stuff i remembering reading when searching up myself. They look like they will be beautiful chickens though.