Why do my two pullet sisters look this different?

[Scottandash16]

A couple of my confirmed girls at a little over 5 mos / 20ish weeks, same date on both pictures. My runty pullet looked dramatically different from her blooming sisters despite age being equal:
View attachment 3614346
I'd want a full body shot to weigh in on sex.

super helpful! Had no idea two of the same age and same breed could be so different!

 

[ShrekDawg]

I don’t see shackle feather on the neck of this youngster.

This is a 13 week cockerel and you can see his neck feathers are fuller and longer.
View attachment 3614341

Also he has a sickle shaped tail and holds himself like a Roo, and he is bottom of the Pecking order here.

Yeah I don’t think it’s a cockerel either

 

[ColtHandorf]

From the pictures I’d says two pullets. But in person I might say cockerel.

 

[LaFleche]

A couple of my confirmed girls at a little over 5 mos / 20ish weeks, same date on both pictures. My runty pullet looked dramatically different from her blooming sisters despite age being equal:
View attachment 3614346
I'd want a full body shot to weigh in on sex.

You runty girl might need a deworming to catch up.

 

[CoopBoots]

You runty girl might need a deworming to catch up.

She absolutely went through a "weak" period where I thought she had coccidiosis, which may have contributed to her slow maturation. Could be I misdiagnosed, but luckily she turned it around and caught up to everyone else. She's over a year old now and an active, healthy member of the flock.