Strange behavior, not ill.

Got an ameracauna mix, from an egg last year. Shes been doing this for close to 6 weeks now. Checked her good for possible egg bound and abdominal masses-nada. Had her in the house for a couple days to feed her up good and continues still to now. She walks around with her tail raised up as if shes alarmed. Ive noticed the other gals will walk like this, but it always seems related to being pecked or something spooked them, its always soon gone and back to normal relaxed state. She has started staying in the coop more, she clucks some, its differant than normal but is not a normal gone broody cluck. She used to hate me but the short time of personal care made her like me and will allow me to hold her and fuss over her. Ive treated her for worms with wazine, dusted her good all over with DE for bugs, inspected her tail area, nothing seems amiss. I just do not know what could be wrong, Her weight is good, everything seems normal xcept for the raised tail. She also pretty much avoids the rest of the flock. Could she just have a perennial case of low girl on the totem pole so she always on high alert? Shes not laying but none of them are now, since they are all molting. Could there have been an injury in the beginning that maimed the muscles in the area but left a sort of paralysis there? Shes a really nice gal, pretty white and blond colors, normal size, unknown as to egg laying-theres too many to know if any one bird is laying or not.
Thanks if anyone has any ideas!

Could you post a picture of her? Ameracauna mix means Easter Egger. What is her age? It could be that she is mixed with a breed of upright tail and now this is showing. Age and picture could help others comment. She sounds lovely and sweet!

I cant do pictures. It is certainly possible that since shes an easter egger, she could be anything mixed with a green/blue egg layer. What kind of chicken normally has a normal upright tail posture? Ive seen pics of show chickens with the posture, but afaik, its not normal all the time with regular barnyard chickens, none other of my gals do that, unless as I said, they are alarmed over something, but then they relax fairly quickly. It just says to me: something differant is going on with her combined with the wanting to hang back from the rest of the flock and staying longer in the coop. I think shes from the EE roo i had last year and my big buff mama, so shes only about 10 mos old. She does not appear sick or ill in any way xcept maybe mentally. I am leaning towards a bad fright and maybe a bang on her tail or underside or even her head when she came down from a bad scare flight.

This just may be another unsolvable chicken mystery.

The worst thing thats happened to me so far has been the day I came home and found one of my big delawares on her back upside down IN the waterer bowl. Dead. I never did figure out what happened, I didnt do a post mortem because i was dog sitting and didnt have time. That was strange. I have had another sudden death, post mortem revealed she was an internal layer-she was FULL of egg yolk-looked like it had gotten infected. Both of them were this years gals, too.
AAhhh, Life with chickens!
Thx.

Yes, life with chickens...I dread when my day comes and one of my sweet chickens die. It was hard enough when it was one of our Cockateils. But that's exactly what can happen with birds.
So she's mixed from your own flock?