Show can I tell she’s laying?

[Frazzemrat1]

i have 11 hens and three pullets. 2 of these pullets are bantam size. Now, I have 2 hamburgs but I could tell when they were widening enough to tell they were laying (plus they’re my only white layers LOL).
Now, the two pullets... one is an EE An day one is an Aruacana. I’m somewhat certain my layer is the EE, because green egg, but her mother was an Aruacana and her father was an ameraucana... or so I was told... so she should be laying blue.

My question... how far apart should a bantam’s pelvic points be? Standards are 3-4 fingers... bantams are...?

Here’s my standard size EE's egg, my silver Hamburg’s egg and my mystery egg.

 

[ChickenCanoe]

Over 2 finger width.
You can use food coloring with a cotton swab. Coat the inside of the cloaca and see which eggs have the food coloring on them.