Not laying but calling in the mornings

She may just be becoming the "rooster". Since you only have pullets your dominate hen is taking charge of everything. She might just be "crowing" in the morning. That is my guess.

I haven't had this problem but my best guess would be to add a rooster.

I betcha she lays an egg soon.  If it sounds like bok bok bok bok BAGAWWWWK - that's the egg song.  They become very vocal right when they are getting ready to lay.

There's not much you can do to get her to stop.  You could open the pop door earlier and take out treats, but I never found this worked.  In fact, my sex link trained me to bring her treats - didn't take her long to figure it out!

does it sound like:

brrrrrrraaaaaawwwwwkkkkkk brrrrrrraaaaaawwwwwkkkkkk brrrrrrraaaaaawwwwwkkkkkk

or:

 buk buk buk buk buk baGAWK  buk buk buk buk buk baGAWK  buk buk buk buk buk baGAWK

or a very rough & gravely almost rooster crow sound "err err, err err, roooo"

Mine does the 1st sound in the morning, low and growl-like but can be loud... for our family it means "I'm up & I want to come out to peck in the lawn!"

The second sound for our family is a warning sound - like there is a cat staring at them from the fence line or deer near them in the woods.

I had a hen that made the 3rd sound, she was trying to be "the rooster" and that was her female version of crowing. Rehomed her when she made that sound 5x in a row at the crack of dawn.

good luck

Hi!  I have a Lucy and Ethel team of chickens too!  They are cuckoo marans.....19 weeks old, no eggs YET!  Soon, I hope!  ~Beulah