Rumpless vs. Very Small Tail?

[NorthernHomestead]

Not specifically a breed question as I hatched out a barnyard mix about a month ago. Daddy's definitely a BO, but the moms are a mix of BOs and EE barnyard mixes. One of my pullets (quite sure this one's a girl just comparing her to her broodermates) has all her feathers in, but a microtail compared to the rest. Just some scant fuzz. How old before you know if a chicken is actually rumpless? I can already see she's an EE cross. There are speckles on her back and a bit of black edging on some of her wing feathers. But my two roos are BOs from TS and the nearest flock lives a bit over a mile away (not walking distance in my winter).

If it's important, all my hens have tails.

Just wondering if it's something to concern myself about as far as egg laying problems in the future. I'd snap a pic, but these babies scatter too quickly in the brooder for me to catch safely.

 

[Amer]

Look for the uropygium. If she has the "tail head" she is not rumpless, but she may be "tailless."

 

[Amer]

However, this shouldn't affect egg production.

 

[NorthernHomestead]

Please don't judge the mess in the brooder. It was just cleaned last night, but with 25 month old chicks, it gets messy very quickly. I was able to get some not-so-great pictures of her. Pics 1-3 she's the top left yellow ball.