With the tails as they are I would say pullet, some females do and can become redder earlier than others even of the same breed. While you don't have crowing, your all good :D
Yes if you hear crowing you have a boy. I'm 50/50 with these right now as the redness makes me think cockerel but the tails make me think pullet.
Did you buy them from a breeder as female?
Hi :welcome
Glad you could join us here! How old is your bird? It does look rather red with pronounced wattles and comb. Is it more red than your other ones?
We do have a what breed gender section you could pop by ~ https://www.backyardchickens.com/f/15/what-breed-or-gender-is-this