Help gendering NONE pure breed Rhode Island Red

[Paz]

So I got four none pure breed Rhode Island reds form this woman a couple months ago and I need help sexing them. They're about four months old, two of them are two weeks younger.
I was told one of them is most likely a rooster but he looks pretty much the same as his twin sister. He does have a tail, and she doesn't. Any way, I NEED to know wether they're both hens, or both cocks. They're both acting like bitches, and also pretty quite, but the one who's supposed to be a cockerel is a bit braver.
I used to have a couple of Rhode Island Whites, and the rooster was very cocky from the very second he entered to coop (got them at 5-6months old), so I would like to know if my new boy is just too young, or maybe I can't tell his gender clearly because his sister is also a boy.
Also, it would be cool if you tell me the gender of them ALL.
Thanks a lot for the help
Rooster? and younger sibling
Rooster and twinRooster? Right, sister? Middle, younger siblings left
Cock? Front, younger brother? Back

 

[Sussex19]

Photo 1 cockerel at the front pullet at the back, photo 2 cockerel on the right photo 3 cockerel on the right, and 4 cockerel at the front, probably a pullet at the back.
I'm not very confident with these, and some of the pictures aren't quite clear enough for me, so this is just what stands out.
Someone more experienced can probably do a better job.

 

[MysteryChicken]

So I got four none pure breed Rhode Island reds form this woman a couple months ago and I need help sexing them. They're about four months old, two of them are two weeks younger.
I was told one of them is most likely a rooster but he looks pretty much the same as his twin sister. He does have a tail, and she doesn't. Any way, I NEED to know wether they're both hens, or both cocks. They're both acting like bitches, and also pretty quite, but the one who's supposed to be a cockerel is a bit braver.
I used to have a couple of Rhode Island Whites, and the rooster was very cocky from the very second he entered to coop (got them at 5-6months old), so I would like to know if my new boy is just too young, or maybe I can't tell his gender clearly because his sister is also a boy.
Also, it would be cool if you tell me the gender of them ALL.
Thanks a lot for the help
Rooster? and younger sibling
Rooster and twinRooster? Right, sister? Middle, younger siblings left
Cock? Front, younger brother? Back

They look pure bred, nice, & dark red plumage. Body is correct, leg color correct, comb type correct.

 

[Paz]

Photo 1 cockerel at the front pullet at the back, photo 2 cockerel on the right photo 3 cockerel on the right, and 4 cockerel at the front, probably a pullet at the back.
I'm not very confident with these, and some of the pictures aren't quite clear enough for me, so this is just what stands out.
Someone more experienced can probably do a better job.

Thanks

 

[Paz]

They look pure bred, nice, & dark red plumage. Body is correct, leg color correct, comb type correct.

They don’t have a certification. Are pure breed chickens sold without certificates? They were also only 15€ each.

 

[MysteryChicken]

They don’t have a certification. Are pure breed chickens sold without certificates? They were also only 15€ each.

None of mine have a certificate, & I have some purebreds.

 

[Paz]

None of mine have a certificate, & I have some purebreds.

Interesting so it isn’t like cats and dogs

 

[MysteryChicken]

Interesting so it isn’t like cats and dogs

No.

 

[Paz]

Update!
The cockerels is a cock and the twin sister is most likely also.