No feathers on Belly/Breast

[Woodys Chickins]

I have 5 hens (1 Delaware, 2 RI Reds, 1 Ameracauna, 1 half-breed mix); all are 1yrs old. The Ameracauna doesn't have belly feathers and her breast is quite visible. She doesn't have any behavior issues and acts just like the other 4 girls. A few weeks ago she was broody, staying in the egg box nearly all the time. She's over that now. She eats like the others--although she doesn't seem to "chow down" as quickly as the others. She runs, plays, behaves normal. She rarely gets pecked on, but she's not afraid to dish-out pecking if the others (especially the Reds) get close to whatever she's eating or messing with.
I treated them all for mites/lice (preventative) using Ivermectin drops (4 per bird...neck, wings, and "down there"). First treatment was 10days ago; followed with 2nd treatment yesterday.
Other than no feathers on her belly (she is a bit on the skinny side), she seems perfectly normal.
((None of them have molted yet)) South Texas is getting into hot summer, but they have plenty of shade and water. they have access to feed whenever they want ///Kalmbach Feeds All Natural Henhouse Reserve 17% Protein Premium Layer feed//.

Any thoughts on why she's got a naked belly?

 

[AntiqueB]

Broody girls will pluck their breast feathers out so they can keep eggs warmer. It's really nothing to worry about; the feathers will grow back eventually!

 

[Woodys Chickins]

Broody girls will pluck their breast feathers out so they can keep eggs warmer. It's really nothing to worry about; the feathers will grow back eventually!

Thank you! Wasn't sure. 5**