I am not a social structure chicken expert, but I was in a similar situation with other species.We took in a handicap and a friend of hers (hens) now the handicap we call Thelma and her friend is Louise.
It sounds like you have such a kind heart — Thelma is lucky to have you looking out for her!
I think your idea could work really well. Housing Thelma with the younger pullets in a separate coop would likely help her build confidence without the stress of the older flock bullying her. Young pullets are usually more accepting (depending on age, sex, etc), especially since they’re still finding their own place in the world and not as territorial yet.
As they all free-range together during the day, they’ll naturally start forming bonds across the two groups. Over time, this could make eventual integration smoother if you ever want them all to share one coop. Just keep an eye on how they interact during free-range time — if everyone seems peaceful, that’s a great sign.
You’re doing exactly the right thing by prioritizing her comfort and safety. Thelma deserves a happy, low-stress life, and it’s clear she’s getting it with you.
