Feather loss on frizzle silkie. I don’t know if it’s mites. Help!

[Alic3]

Hey everyone! So my bantam frizzle silkie Midnight, for about 5 months, has been experiencing feather loss on her back, tail, near the vent, and partly on her neck. I've tried DE on her once, but it did not help much. An 8lb Cochin rooster was overnating, and I think that is what started her feather loss. I'm very confused about what she might have because I first thought it was pecking, and I separated her from the bullies, but that made things worse. I have just been leaving her with our 5-week-old chicks, who I have made sure don't peck her, and she seems to be doing a bit better, but it's hard to tell. I have researched what it could be, and most of the time, I see that it's mites. But then I have no idea what type of mite it could be because I've never seen any mites in our cage. My current guess is Depluming mites because I can't see them, and none of my treatments have helped much. I was wondering if anyone has ever had this problem? Also, as a last resort, I will refresh my whole cage. Like blow torch the ground and anywhere it wouldn't catch fire, get new sand and mix it with DE, spray a coop protector everywhere, and for midnight, I read that topical ivermectin can help with De-pluming mites. If anyone knows anything that can help her please tell me!

 

[nuthatched]

She might be a frazzle, meaning the frizzling us to extreme that her feathers break.
It doesn't look like mites.
DE will not help at all and can cause more issues than you have.

 

[Alic3]

Ok! Even if she is a frazzle wouldn't she need a reason for her excessive feather breakage/loss? Or is there another underlying problem?