Have you got an accurate weight on her? I would suggest doing so in order to actually monitor if condition is improving, staying the same, or decreasing. But I don't think weight is a total indicator. I will also state that if she is a pullet and not a hen then she won't yet be filled into her full grown adult status but will still have her teenager body figure. Mature birds will often weigh a pound more than their pullet/cockerel phase. Also get a good ideal of where her keel bone score is.. understanding that EE are NOT double breasted or even big breasted.
This was a good read..
https://thepoultrypages.blogspot.com/2016/06/why-can-i-feel-my-chickens-keel-breast.html
She may not be able to spread oil from the preen gland to keep the feathers in nice condition. I wonder if anyone has worked out a way to help them with this.. since staying warm/dry with feathers reduces calorie need in addition to the parasite protection that preening provides. Being cold increases calorie need and may reduce body condition if there isn't enough intake during the daylight hours, like far north winter time short days. Skin condition should always remain light pink. Bright red or irritated angry, or scabbing of any sort would indicate external parasite conditions. She may need help removing sheaths when new feathers come in
Egg laying hormone is influenced by daylight hours (and age). When daylight (or house light hours) decreases so will her egg production. Their first laying season is often gang busters. My point PARTLY is if you wanted to decrease laying to increase condition, it might be doable. I don't truly think it's needed, but as an avid over thinker it crossed my mind as a possibility IF I were desperate.
Consider measuring and monitoring her feed intake for a period and see where that stands.. when free ranging my birds average .18- .20# of flock raiser.. noting corn has the same amount of calories as any other protein or carbohydrate but it does not have the added vitamins, minerals, and amino acids that a formulated ration does. IF weight gain was the ONLY goal then adding fat into the evening feed would do that (aside from tubing).. or by giving the corn after the birds already filled up on their feed so they then gorge themselves on the corn getting calories they don't need (in most cases) is the only way I could see corn making a difference to add weight, for discussion purposes not harping here.
So if I wanted to boost her.. I would on occasion like during molt for example (once or twice per month for 2-3 days in a row) offer a supplement. In the US (adding your general location to your profile helps) my top 3 suggestions not in any particular order are..
1. Poultry Nutri drench, easily added to water
Rooster Booster (brand)
2. Poultry Cell, easiest added in moist feed as it separates in water
or
3. Poultry Booster
Regarding internal parasites.. I usually recommend a fecal float/count before treatment unless you've seen something. Only large round worms and tape worms can be seen in droppings, usually under heavy load conditions. After getting a decade of negative results.. come to find out they (the microscopic eggs) can pass intermittently. My vet now recommends once yearly treatment regardless.. for MY location, weather patterns, soil type, wildlife load, stock density, etc. EACH individual within a flock carries their own load that may be different from their mates due to differences in immune systems, bathing habits, etc. Still when one gets treated they often all do
Sounds/LOOKS like she is doing pretty good with you already!
Soon you'll be the one sharing all the tips that worked (and didn't) for your special gal.
Does she have a name?
