Sexing my almost 5 week old babies

[Valalilly]

My favorite hen was broody and I gave her some eggs. Lo and behold on day 18 ALL 6 hatched. She's an amazing momma, but now that they babies are getting bigger I'm wondering how many roos I have.
I can truly only keep 1 roo max

The white one (Bianca) is no doubt a roo, but the rest????

They are all so darn cute, I want to keep them all, but I highly doubt it'll be 5 hens and 1 roo.

They're all mixed breeds with most likely a Rhode island red daddy.
I added a few photos from when they were 3 days old because I can and everyone loves tiny little baby chickies.

(Edit: replaced the photos with photos with their names for ease)

 

[nuthatched]

The white on and red one are cockerels but it might be too early on the others.

 

[Valalilly]

And a sideways picture of the one who wouldn't pose. Cleopatra has pretty eyeliner and every chick with eyeliner I've ever had has been a hen. So I kinda figured ... Not sure though....